CN101522935B

CN101522935B - Process for production of aluminum alloy formings, aluminum alloy formings and production system

Info

Publication number: CN101522935B
Application number: CN2007800364415A
Authority: CN
Inventors: 冈本康夫
Original assignee: Showa Denko KK
Current assignee: Resonac Holdings Corp
Priority date: 2006-08-01
Filing date: 2007-07-31
Publication date: 2012-09-26
Anticipated expiration: 2027-07-31
Also published as: EP2048259A1; CN101522935A; KR20090046868A; EP2048259A4; JPWO2008016169A1; US20100006192A1; WO2008016169A1

Abstract

The invention provides a process for production of aluminum alloy formings superior to conventional aluminum alloy forgings in mechanical strength at high temperature. A process for production of aluminum alloy formings by forging a stock consisting of a continuously cast rod made of an aluminum alloy, in which the aluminum alloy contains 10.5 to 13.5% by mass of Si, 2.5 to 6% by mass of Cu, 0.3 to 1.5% by mass of Mg, and 0.8 to 4% by mass of Ni and satisfies the relationship: Ni (% by mass) = [-0.68 OECu(% by mass) + 4.2(% by mass)] and which comprises the step (82) of preheat treatment of the stock, the heating step (87) of forging the stock, and the step (89) of postheat treatment of an aluminum alloy forming as the heat treatment/heating steps, with the step (82) involving the treatment of keeping the stock at -10 DEG C to 480 DEG C for 2 to 6 hours.

Description

The method of manufacture of duraluminum molding, duraluminum molding and production system

Technical field

The present invention relates to have continuous casting rod that use processed by duraluminum as the method for manufacture of the duraluminum molding of the forging and molding operation of base material, duraluminum molding with and production system.

Background technology

In recent years, vehicles such as brougham, two wheeler (following be called simply " automobile ") for high performance, for the response environment problem, for internal combustion engine, have been discussed the piston that adopts the aluminium forging.Can make the drive element lightweight of the oil engine of piston etc., the load when seeking to make internal combustion engine operation reduces, output rating improves, fuel consumption reduces.The internal combustion engine of duraluminum system adopts casting article all the time morely, but casting article are difficult to suppress to cast the subsurface defect of time generation, for safe design intensity, the wall thickness of surplus must be set, and lightweight is difficult.

Therefore, discussed to utilize and to have suppressed the lightweight that aluminum alloy forged article that subsurface defect takes place are realized piston.

Aluminum alloy forged method of manufacture with the base material in the past comprises: adopt common molten metal manufacturing process to prepare the operation of molten aluminium alloy; Then any method among all continuous metal cast processs of this molten aluminium alloy employing continuous metal cast process, D.C.casting method (DC casting), hot top casting etc. is cast, make the operation of aluminium alloy cast ingot; Then this ingot casting is implemented to homogenize thermal treatment, carry out the operation that the duraluminum crystalline homogenizes.And, implement to forge with base material (ingot casting) to aluminum alloy forged, and then implement the T6 thermal treatment of JIS (JIS), produce aluminum alloy forged molding thus.

In addition, about 6000 being alloy, it is alloy with this thermal treatment elliptical 6000 maybe that TOHKEMY 2002-294383 communique (patent documentation 1) discloses the heat treated temperature that suppresses to homogenize.

, in patent documentation 1, the mechanical characteristics during to high temperature is not discussed.

On the other hand; Can be manufactured on the duraluminum molding more excellent than the physical strength under the high temperature of aluminium forging in the past is the following TOHKEMY 2005-290545 communique (patent documentation 2) of purpose; A kind of method of manufacture with continuous casting rod that use processed by duraluminum as the duraluminum molding of the forging and molding operation of base material is disclosed; Wherein, Duraluminum contains the Si of 10.5 quality %～13.5 quality %, the Fe of 0.15 quality %～0.65 quality %, the Cu of 2.5 quality %～5.5 quality % and the Mg of 0.3 quality %～1.5 quality %; This method of manufacture comprises thermal treatment and heating process; Said thermal treatment and heating process comprise preceding heat treatment step to the base material, to the forging of base material add the heating process in man-hour, to the post-heat-treated operation of duraluminum molding, preceding heat treatment step is included in-10 ℃～480 ℃ processing that keep 2 hours～6 hours down.

, require the efficient of further oil engine to improve the raising with output rating in recent years, its result, for employed parts wherein, the physical strength of requirement under higher temperature.

Therefore, for the aluminum alloy forged article that turn to target with light weight more, just seeking the method for manufacture of the duraluminum molding that the physical strength when making higher temperature (for example, 350 ℃ under fatigue strength) improves than aluminum alloy forged article in the past.

The present invention In view of the foregoing accomplishes, and its objective is the method for manufacture, duraluminum molding and the production system that are provided at the duraluminum molding more excellent than the physical strength under the aluminum alloy forged higher temperature in the past.

Summary of the invention

(1) in order to achieve the above object; The 1st invention of the present invention; It is a kind of method of manufacture of duraluminum molding; It has continuous casting rod that use forms by the duraluminum forging and molding operation as the base material, it is characterized in that duraluminum contains the Si of 10.5 quality %～13.5 quality %, the Cu of 2.5 quality %～6 quality %, the Mg of 0.3 quality %～1.5 quality % and the Ni of 0.8 quality %～4 quality %; And satisfy the relational expression of Ni (quality %) >=(0.68 * Cu (quality %)+4.2 (quality %)); This method of manufacture comprises thermal treatment and heating process, and said thermal treatment and heating process preheat operation before comprising preceding heat treatment step to the base material, the forging processing to the base material, to the post-heat-treated operation of duraluminum molding, and preceding heat treatment step is included in-10 ℃～480 ℃ processing that keep 2 hours～6 hours down.

(2) the 2nd invention of the present invention is characterized in that in the method for manufacture of duraluminum molding of above-mentioned the 1st invention, the thermal treatment temp of preceding heat treatment step is 200 ℃～370 ℃.

(3) the 3rd invention of the present invention is characterized in that in the method for manufacture of duraluminum molding of above-mentioned the 1st invention, the thermal treatment temp of preceding heat treatment step is-10 ℃～200 ℃.

(4) the 4th invention of the present invention is characterized in that in the method for manufacture of duraluminum molding of above-mentioned the 1st invention, the thermal treatment temp of preceding heat treatment step is 370 ℃～480 ℃.

(5) the 5th invention of the present invention is characterized in that, in the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 4 invention, the post-heat-treated operation is not implement solution treatment and kept 1 hour～10 hours down at 170 ℃～230 ℃.

(6) the 6th invention of the present invention is characterized in that, in the method for manufacture of the duraluminum molding that above-mentioned the 1st invention～the 5 is invented, duraluminum contains the Fe of 0.15 quality %～0.65 quality %.

(7) the 7th invention of the present invention is characterized in that, in the method for manufacture of the duraluminum molding that above-mentioned the 1st invention～the 6 is invented, duraluminum contains the P of 0.003 quality %～0.02 quality %.

(8) the 8th invention of the present invention; It is characterized in that; In the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 7 invention, duraluminum contains any or the two or more combinations among the Ca of Na, 0.001 quality %～0.02 quality % of Sb, the 0.0005 quality %～0.015 quality % of Sr, the 0.1 quality %～0.35 quality % of 0.003 quality %～0.03 quality %.

(9) the 9th invention of the present invention; It is characterized in that; In the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 8 invention, duraluminum contains any or the two or more combinations among the Ti of V, 0.01 quality %～0.2 quality % of Zr, the 0.01 quality %～0.15 quality % of Cr, the 0.04 quality %～0.3 quality % of Mn, the 0.05 quality %～0.5 quality % of 0.1 quality %～1.0 quality %.

(10) the 10th invention of the present invention is characterized in that, in the method for manufacture of the duraluminum molding that above-mentioned the 1st invention～the 9 is invented, the working modulus at position in the forging and molding operation, that require high temperature resistant fatigue strength is below 90%.

(11) the 11st invention of the present invention is characterized in that, in the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 10 invention, in the forging and molding operation, pre-heating temperature is 380 ℃～480 ℃ before the processing.

(12) the 12nd invention of the present invention; It is characterized in that; In the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 11 invention, it is that to adopt continuous metal cast process be that the duraluminum of liquidus line+40 ℃～liquidus line+230 ℃ is cast and obtained to the medial temperature of liquation in 80 (mm/ minute)～2000 (mm/ minute) that the continuous casting rod makes casting speed.

(13) the 13rd invention of the present invention; It is the duraluminum molding that adopts the arbitrary method of manufacture in the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 12 invention to make; It is characterized in that; In tissue, the aggregate of the reticulattion of the crystallisate that forms during continuous casting or needle crystal thing or crystallisate is also partly residual after shaping and thermal treatment.

(14) the 14th invention of the present invention; It is the duraluminum molding that adopts the arbitrary method of manufacture in the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 12 invention to make; It is characterized in that the area ratio/occupancy ratio of eutectic Si is more than 8%, the median size of eutectic Si is below the 5 μ m; Needle-like is than being that eutectic Si more than 1.4 is more than 25%; The area ratio/occupancy ratio of intermetallic compound is more than 1.2%, and the median size of intermetallic compound is more than the 1.5 μ m, and length is that 3 μ m aggregate above, intermetallic compound or contacted intermetallic compound is more than 30%.

(15) the 15th invention of the present invention is the duraluminum molding that the 13rd invention or the 14th that is shaped as having the duraluminum system engine piston in crown position, skirt section is invented, and it is characterized in that the high temperature fatigue intensity at above-mentioned crown position is more than the 50MPa.

(16) the 16th invention of the present invention; It is the production system of will a series of operation constructing as continuous lines from liquation to the duraluminum molding; It is characterized in that, comprise the operation of any method of manufacture among the method for manufacture of duraluminum molding of above-mentioned the 1st invention～the 12 invention.

According to (1) described the 1st invention, duraluminum contains Si, Cu, Mg and Ni, therefore can access high temperature fatigue intensity and forging property, ductility, all good molding of toughness.In addition, Ni and Cu component satisfy the relational expression of Ni (quality %) >=(0.68 * Cu (quality %)+4.2 (quality %)), and therefore the fatigue strength characteristic under higher temperature improves.

In addition, must change the alloy trial-production molding of the many levels of alloy composition cause, and the evaluation of high temperature fatigue intensity also is the evaluation that needs complex apparatus and more time, the alloy designs that therefore particularly has the fatigue strength high temperature under is difficult in the past.

; The above-mentioned relation formula of the application of the invention relates to alloy composition as index; Can easily obtain having the alloy of the fatigue strength characteristic under higher temperature, and, even can access the duraluminum molding that also has excellent physical strength when comparing 350 ℃ high temperature.

More particularly, for example, the fatigue strength under 350 ℃ of after down keeping 100 hours 350 ℃ is more than the 33MPa.These characteristics for example are the desired characteristics in crown position of the internal combustion engine that contacts with high-temperature atmosphere.Therefore, the duraluminum molding of the application of the invention, than internal combustion engine in the past, can thin-walled property, the lightweight of internal combustion engine becomes possibility.And, can the desired lightweight of respective market, can realize that the burnup of oil engine reduces, output rating improves.

According to (2) described the 2nd invention, the thermal treatment temp of heat treatment step is 200 ℃～370 ℃ before making, so high temperature fatigue intensity more takes into account with forging property, ductility, toughness, can access better molding.

According to (3) described the 3rd invention, the thermal treatment temp of heat treatment step is-10 ℃～200 ℃ before making, and therefore can access the better molding of high temperature fatigue intensity.But forging property, ductility, toughness are 200 ℃～370 ℃ moulding article reduction than thermal treatment temp.

According to (4) described the 4th invention, the thermal treatment temp of heat treatment step is 370 ℃～480 ℃ before making, and therefore can access forging property, ductility, the better molding of toughness.But high temperature fatigue intensity is 200 ℃～370 ℃ moulding article reduction than thermal treatment temp.

According to (5) described the 5th invention, in the post-heat-treated operation, do not implement solution treatment and kept 1 hour～10 hours at 170 ℃～230 ℃, therefore can access the better molding of high temperature fatigue intensity.But ductility, toughness are than implementing solution treatment and reducing at 170 ℃～230 ℃ moulding article that kept 1 hour～10 hours.

According to (6) described the 6th invention, duraluminum contains the Fe of 0.15 quality %～0.65 quality %, so crystallization goes out, and Al-Fe is, Al-Fe-Si is, the particle of Al-Ni-Fe system, and high-temperature machinery intensity is improved.And the Fe content of 0.15 quality %～0.65 quality % suppresses the increase of thick crystallisate, and forging property, high temperature fatigue intensity, toughness are improved.

According to (7) described the 7th invention; Duraluminum contains the P of 0.003 quality %～0.02 quality %; P produces primary crystal Si, is preferred making under the preferential situation of wearability, in addition; P has the effect of refinement primary crystal Si, plays the effect that forging property, ductility and high temperature fatigue intensity that inhibition causes by the primary crystal Si that produces reduce.And the P content of 0.003 quality %～0.02 quality % suppresses the increase of thick primary crystal Si, and forging property, high temperature fatigue intensity, toughness are improved.

According to (8) described the 8th invention; Duraluminum contains any or the two or more combinations among the Ca of Na, 0.001 quality %～0.02 quality % of Sb, the 0.0005 quality %～0.015 quality % of Sr, the 0.1 quality %～0.35 quality % of 0.003 quality %～0.03 quality %; Therefore can suppress the generation of primary crystal Si, be preferred making under forging property, ductility, the preferential situation of toughness.And the content of the Sr of this scope, Sb, Na, Ca suppresses the generation of primary crystal Si, and forging property, toughness, high temperature fatigue intensity are improved.

According to (9) described the 9th invention; Duraluminum contains any or the two or more combinations among the Ti of V, 0.01 quality %～0.2 quality % of Zr, the 0.01 quality %～0.15 quality % of Cr, the 0.04 quality %～0.3 quality % of Mn, the 0.05 quality %～0.5 quality % of 0.1 quality %～1.0 quality %; Therefore the compound crystal of Al-Mn system, Al-Fe-Mn-Si system, Al-Cr system, Al-Fe-Cr-Si system, Al-Zr system, Al-V system, Al-Ti system goes out or separates out, and the high-temperature machinery intensity of duraluminum is improved.And the content of the Mn of this scope, Cr, Zr, V, Ti suppresses the increase of thick crystallisate, and forging property, high temperature fatigue intensity, toughness are improved.

According to (10) described the 10th invention; The working modulus that makes position in the forging and molding operation, that require high temperature resistant fatigue strength is below 90%; Therefore appropriateness block, the reticulattion of appropriate residual crystallisate, acicular structure, aggregate, therefore can access ductility, toughness and the good molding of high temperature fatigue intensity.

According to (11) described the 11st invention, make in the forging and molding operation, therefore pre-heating temperature is 380 ℃～480 ℃ before the processing, can access high temperature fatigue intensity and forging property, ductility, the good molding of toughness.

According to (12) described the 12nd invention; Making casting speed is that to adopt continuous metal cast process be that the duraluminum of liquidus line+40 ℃～liquidus line+230 ℃ is cast and obtained the continuous casting rod with the medial temperature of liquation in 80 (mm/ minute)～2000 (mm/ minute); Therefore in the reticulattion that can obtain even, fine crystallisate, acicular structure, aggregate, can access high temperature fatigue intensity and forging property, ductility, the good molding of toughness.

According to (13) described the 13rd invention; In tissue; The aggregate of the reticulattion of the crystallisate that forms during continuous casting or needle crystal thing or crystallisate is also partly residual after shaping and thermal treatment, therefore can access high temperature fatigue intensity and forging property, ductility, the good molding of toughness.

According to (14) described the 14th invention; The area ratio/occupancy ratio of eutectic Si is more than 8%; The median size of eutectic Si is below the 5 μ m; Needle-like is than being that eutectic Si more than 1.4 is more than 25%, and the area ratio/occupancy ratio of intermetallic compound is more than 1.2%, and the median size of intermetallic compound is more than the 1.5 μ m; Length is that 3 μ m aggregate above, intermetallic compound or contacted intermetallic compound is more than 30%, therefore can obtain high temperature fatigue intensity and forging property, ductility, the good molding of toughness more effectively.

According to (15) described the 15th invention, the high temperature fatigue intensity at crown position is more than the 50MPa, therefore has sufficient high temperature fatigue intensity, can be used for the crown position of internal combustion engine etc. with being well suited for.

According to (16) described the 16th invention; A series of operation from molten metal to the duraluminum molding is constructed as continuous lines; At least the operation that comprises the duraluminum molding method of manufacture of above-mentioned any in this operation, the fatigue strength characteristic under higher temperature improves.

In addition, must change the alloy trial-production molding of alloy composition by many levels, and the evaluation of high temperature fatigue intensity also is the evaluation that needs complex apparatus and more time, the alloy designs that therefore particularly has the fatigue strength high temperature under is difficult in the past.

; The above-mentioned relation formula of the application of the invention designs alloy composition as index; Can easily obtain having the alloy of the fatigue strength characteristic under higher temperature, and, even can access the duraluminum molding that also has excellent physical strength when comparing 350 ℃ high temperature.

More particularly, for example, the fatigue strength under 350 ℃ of after down keeping 100 hours 350 ℃ is more than the 33MPa.These characteristics for example, are the required characteristics in crown position of the internal combustion engine that contacts with high-temperature atmosphere.Therefore, the duraluminum molding of the application of the invention, than internal combustion engine in the past, thin-walled property more, the lightweight of internal combustion engine becomes possibility.And, can tackle the required lightweight in market, can realize that the burnup of oil engine reduces, output rating improves.

Description of drawings

The 1st figure is the figure of expression as the forging production system of an example of the production line of realizing manufacturing process of the present invention.

The 2nd figure is near the figure of the example the mold of the casting apparatus that uses among the present invention of expression.

The 3rd figure is near another the routine figure the mold of the casting apparatus that uses among the present invention of expression.

The 4th figure is the long figure of effective mould of the casting apparatus that uses among the present invention of expression.

The 5th figure is another routine figure of the casting apparatus that uses among the present invention.

The 6th figure is the figure of relation of the containing ratio of Ni and the Cu of explanation in the duraluminum.

The 7th figure (a) is the plat of piston with shape of embodiments of the invention 17,18 and comparative example 11～13.The 7th figure (b) is the FV of the piston shown in the 7th figure (a).

The 8th figure is the VIII-VIII line sectional view of the 7th figure (a).

Embodiment

Alloy composition to molding of the present invention describes.

The molten aluminium alloy that uses in the present invention; Be adjusted to the Si that contains 10.5 quality %～13.5 quality % (being preferably 11.5 quality %～13 quality %), the Cu of 2.5 quality %～6 quality % (being preferably 3.5 quality %～5.5 quality %), the Mg of 0.3 quality %～1.5 quality % (being preferably 0.5 quality %～1.3 quality %), the Ni of 0.8 quality %～4 quality % (being preferably 1.8 quality %～3.5 quality %); And satisfy Ni (quality %) >=(0.68 * Cu (quality %)+AA (quality %)) (wherein; AA is a constant; AA >=4.2 are preferably AA >=4.7.) the composition of relational expression.

Si: the distribution through eutectic Si improves high-temperature machinery intensity, wearability, separates out the Mg2Si particle with the Mg coexistence, and high-temperature machinery intensity is improved.Si is during less than 10.5 quality %, and above-mentioned effect is little, and when surpassing 13.5 quality %, the crystallization of primary crystal Si increases, and high temperature fatigue intensity, ductility, toughness are reduced.

Ni: generation Al-Ni system, Al-Ni-Cu are crystallisate, and high-temperature machinery intensity is improved.Ni is during less than 0.8 quality %, and above-mentioned effect is little, and when surpassing 4 quality %, thick crystallisate increases, and forging property, high temperature fatigue intensity, ductility, toughness are reduced.

Cu: separate out CuAl ₂Particle, and generation Al-Cu is, Al-Ni-Cu is a crystallisate, and high-temperature machinery intensity is improved.Cu is during less than 2.5 quality %, and above-mentioned effect is little, and when surpassing 6 quality %, the thick crystallisate of Al-Cu system increases, and forging property, high temperature fatigue intensity, ductility, toughness are reduced.

Mg: separate out Mg with the Si coexistence ₂The Si particle improves high-temperature machinery intensity.Mg is during less than 0.3 quality %, and above-mentioned effect is little, when surpassing 1.5 quality %, and Mg ₂The thick crystallisate of Si increases, and forging property, high temperature fatigue intensity, ductility, toughness are reduced.

And in the present invention, the composition of Ni and Cu need satisfy the relational expression of Ni (quality %) >=(0.68 * Cu (quality %)+AA (quality %)) (wherein, AA is a constant, and AA >=4.2 are preferably AA >=4.7).This is because satisfy this relational expression through Ni and Cu, and the fatigue strength characteristic under higher temperature improves.In addition, preparing and make that constant A A is the duraluminum molding more than 4.7, help the generation of the netted or acicular intermetallic compound of hot strength to increase, is preferred therefore.

The mechanism that above-mentioned fatigue strength characteristic improves is still indeterminate, but can infer as follows.Thought Al-Ni system, Al-Ni-Cu, the Al-Cu that helps most high-temperature machinery intensity to improve be crystallisate and under hot environment the Cu of solid solution in aluminum substrate.The relation of Cu amount and Ni amount of utilizing the solid solution of these crystallisates and Cu to produce the raising of high-temperature machinery intensity is effectively derived by following formula.

Used the molding of such duraluminum, as preferred value, the fatigue strength under 350 ℃ is more than the 33MPa, further to be preferably more than the 43MPa.And the fatigue strength under 300 ℃ is more than the 55MPa.

This molten metal preferably contains a kind of or two or more among the Ti of V, 0.01 quality %～0.2 quality % (being preferably 0.02 quality %～0.1 quality %) of Zr, the 0.01 quality %～0.15 quality % (being preferably 0.05 quality %～0.1 quality %) of Cr, the 0.04 quality %～0.3 quality % (being preferably 0.1 quality %～0.2 quality %) of Mn, the 0.05 quality %～0.5 quality % (being preferably 0.1 quality %～0.3 quality %) of 0.1 quality %～1 quality % (being preferably 0.2 quality %～0.5 quality %).This is because the containing of Mn, Cr, Zr, V, Ti, can crystallization or separate out the compound of Al-Mn system, Al-Fe-Mn-Si system, Al-Cr system, Al-Fe-Cr-Si system, Al-Zr system, Al-V system, Al-Ti system, and the high-temperature machinery intensity of duraluminum is improved.Mn less than 0.1 quality %, Cr less than 0.05 quality %, Zr less than 0.04 quality %, V less than 0.01 quality %, Ti during less than 0.01 quality %; Above-mentioned effect is little; Mn surpasses 1.0 quality %, Cr surpasses 0.3 quality %, V above 0.15 quality %, when Ti surpasses 0.2 quality % above 0.5 quality %, Zr; Thick crystallisate increases, and forging property, high temperature fatigue intensity, toughness are reduced.

And then, preferably contain the Fe of 0.15 quality %～0.65 quality % (being preferably 0.3 quality %～0.5 quality %), the particle crystallization of Al-Fe system, Al-Fe-Si system, Al-Ni-Fe system is gone out, improve high-temperature machinery intensity.Fe is during less than 0.15 quality %, and above-mentioned effect is little, and when surpassing 0.65 quality %, the thick crystallisate of Al-Fe system, Al-Fe-Si system, Al-Ni-Fe system increases, and forging property, high temperature fatigue intensity, ductility, toughness are reduced.

In addition, the P that preferably contains 0.003 quality %～0.02 quality % (being preferably 0.007 quality %～0.016 quality %).P can make primary crystal Si produce, and is preferred making under the preferential situation of wearability therefore, in addition, has the effect of refinement primary crystal Si, plays the effect that forging property, ductility, high temperature fatigue intensity that inhibition causes by the primary crystal Si that produces reduce.P is during less than 0.003 quality %, and the effect of refinement primary crystal Si is little, produces thick primary crystal Si at the center of ingot casting, and forging property, high temperature fatigue intensity, ductility, toughness are reduced.When P surpassed 0.02 quality %, the generation of primary crystal Si increased, and forging property, high temperature fatigue intensity, ductility, toughness are reduced.

In addition; When containing a kind of or two or more among the Ca of Na, 0.001 quality %～0.02 quality % (being preferably 0.005 quality %～0.01 quality %) of Sb, the 0.0005 quality %～0.015 quality % (being preferably 0.001 quality %～0.01 quality %) of Sr, the 0.1 quality %～0.35 quality % (being preferably 0.15 quality %～0.25 quality %) of 0.003 quality %～0.03 quality % (being preferably 0.01 quality %～0.02 quality %); Therefore effect with refining eutectic Si is preferred.Sr less than 0.003 quality %, Sb less than 0.1 quality %, Na less than 0.0005 quality %, Ca during less than 0.001 quality %; Above-mentioned effect is little; When Sr surpasses 0.03 quality %, Sb surpasses 0.35 quality %, Na above 0.015 quality %, when Ca surpasses 0.02 quality %; Thick crystallisate increases, and perhaps produces casting flaw, and forging property, high temperature fatigue intensity, toughness are reduced.

The ratio of components of the alloying constituent of duraluminum molding, ingot casting for example, can be confirmed through the method that adopts the photoelectric photometry formula ICP Atomic Emission Spectrophotometer device of putting down in writing among the JIS H1305 (the device example: Shimadzu Seisakusho Ltd. makes PDA-5500).

Below based on accompanying drawing embodiment of the present invention is elaborated.

The 1st figure is the figure of expression as the production system of an example of the production line of realizing manufacturing process of the present invention.In the 1st figure, the production system of forged article comprises: flatly cast the continuous casting rod by molten metal, be cut to the casting apparatus 81 of the length of regulation; To implementing heat treated preceding thermal treatment unit 82 by the continuous casting rod of these casting apparatus 81 castings; Through thermal treatment unit 82 thermal treatments before being somebody's turn to do, under the situation that the continuous casting rod bends, corrigent apparatus for correcting 83 is carried out in the bending of continuous casting rod; Remove the apparatus for peeling off 84 of having corrected the outer peripheral portion of crooked continuous casting rod by this apparatus for correcting 83; To be cut to the shut-off device 85 of the cut off machine of the necessary length of forging and molding article by the continuous casting rod that this apparatus for peeling off 84 has been removed outer peripheral portion; To preheat by the cut off machine that this shut-off device 85 cuts out, thus the upsetting device (omitting diagram) that carries out upsetting processing; Be lubrication fittings 86A, 86B to impregnated in the graphite base lubricant or be covered by the base material of this upsetting device upsetting lining lubricant coating graphite base lubricant or the base material that will preheat on the base material that has preheated; And then by base material forging forged article (the roughing finished product that is attached with lubricant that adopts preheating apparatus 87 heating; Preform) forging apparatus 88; To implement the post-heat-treated device 89 of post-heat-treated by the intact goods (forged article) of these forging apparatus 88 forged forgings.

Post-heat-treated device 89; For example, can constitute by the solid solution heating unit 90 of the goods that forged being implemented solution treatment, the quenching device 91 that will quench, ageing treatment device 92 that the forged article that is quenched by this quenching device 91 is implemented ageing treatment by the forged article of these solid solution heating unit 90 heating.Omit the occasion of solution treatment, solid solution heating unit 90 preferably is not set ageing treatment device 92 is set after forging apparatus 88 with quenching device 91.

In addition, apparatus for peeling off 84, upsetting device can omit.In addition, the conveying between each device can adopt automatic conveying device to carry out.In addition, the lining of the lubricant among lubrication fittings 86A, 86B processing is replaceable is that phosphatization (bonde) is handled (phosphate coating processing) device 86C.

At this, preceding thermal treatment unit 82 has base material temperature-10 ℃～480 ℃ functions that keep 2 hours～6 hours.Preheating apparatus 87 has that to make base material temperature be 380 ℃～480 ℃ function.The solid solution heating unit 90 of post-heat-treated device 89 and quenching device 91, having the solid solubility temperature that makes the goods (molding) that forged is 480 ℃～520 ℃ functions of quenching afterwards.The ageing treatment device 92 of post-heat-treated device 89 has the function that the temperature of the goods that forged (molding) is remained on 170 ℃～230 ℃.

Adopt the method for manufacture of production system of the present invention; Be comprise the pole that obtains duraluminum being adopted continuous metal cast process casting implement before heat treated operation, with preceding thermal treatment pole process the method for manufacture of molding that shape goes out roughing finished product operation, after plastic working, carries out the operation of post-heat-treated as the base material through thermoplasticity; Before heat treated temperature be-10 ℃～480 ℃; The base material temperature that thermoplasticity adds man-hour is 380 ℃～480 ℃; In the post-heat-treated operation; It is 480 ℃～520 ℃ that the solid solution heating time makes the temperature of roughing finished product, does not perhaps implement solution treatment and directly satisfies the temperature treatment of 170 ℃～230 ℃ temperature condition, begins to comprise that from casting process each heat treatment step always makes molding.Its result can stably make the molding with ideal physical strength.

As above-mentioned plastic working, can enumerate and forge processing, but method of manufacture of the present invention if heat treated temperature, thermoplasticity add the base material temperature in man-hour, the temperature condition of post-heat-treated before satisfying, then also can make up with rolling processing, extrusion processing.Under any situation, in the control of net of tissue, crystallisate, can both obtain action effect of the present invention.

Duraluminum molding of the present invention can be used as the parts of the physical strength when requiring high temperature with being well suited for.Therefore; For example; The molding of the shape of engine piston constructed in accordance, tappet rod for valve, valve spring holder, cylinder sleeve etc.; Utilize lathe, NC machine tools with automatic tool changer etc. further to carry out mechanical workout as required these moulding article, be configured as desirable shape thus, can be used as the parts use that various goods are used.

For the part of the method for manufacture of using among the present invention, basic clotting method, can adopt any method in known hot top continuous metal cast process, vertical continuous casting method, horizontal casting method, the DC casting.For example can be: remain to hub and horizontal have the inner-wall surface of forcing refrigerative tubular mold and supply with any or the two or more fluids that is selected among gas, liquid lubricant, its thermal degradation gas; End to the tubular mold is supplied with the molten aluminium alloy that contains Si; Form the cylindrical metal liquation; The cylindrical metal liquation is solidified, the horizontal casting method that the ingot casting that forms is pulled out from the other end of tubular mold in the tubular mold.Below describe for the situation that applies the present invention to the horizontal casting method.

The 2nd figure is near the figure of the example the mold of the casting apparatus that uses among the present invention of expression.Dispose tundish (tundish) 250, refractory materials system tabular body 210, tubular mold 201, make the alloy liquation 255 that stores in tundish 250 be supplied in the tubular mold 201 via refractory materials system tabular body 210.Tubular mold 201 is held and makes mold hub 220 be approximate horizontal.Internal configuration at tubular mold 201 has the pressure cooling body, disposes the pressure cooling body that solidifies ingot casting 216 in the outlet of tubular mold 201, makes alloy liquation 255 become and solidifies ingot casting 216.In Fig. 2, force the example of refrigerative mechanism as solidifying ingot casting 216, be provided with cool water shower device 205.Near the outlet of tubular mold 201, be provided with drive unit (not diagram), thereby make the ingot casting of forcing to cool off 216 that solidifies pull out casting continuously with certain speed.And then, dispose the synchronization cutting mechanism (not diagram) that the cast rod of pulling out is cut to the length of regulation.

Adopt near another example of mold of the device that uses among the 3rd figure explanation the present invention.The 3rd figure is an example of expressing the DC casting machine with the schematic sectional view.In this DC casting machine, molten aluminium alloy 1 imports in duraluminum system or the fixed junker mold 5 made of copper through groove 2, dip-tube 3 and float-type divider 4.Junker mold 5 is cooled off by water coolant 5A.Import to the molten aluminium alloy 6 in the junker mold 5, with part that junker mold 5 contact in form solidified shell (solidificationshell) thereby 7 contractions, the aluminium alloy cast ingot 7A that solidifies utilizes counterdie (die) 9 to pull out from junker mold 5 downwards.At this moment, aluminium alloy cast ingot 7A is further cooled off by the water-cooled jet of being supplied with by junker mold 58, fully solidifies.If counterdie 9 arrives movably bottom, then aluminium alloy cast ingot 7A is cut off in the position of regulation, thereby takes out.

Be back to the 2nd figure and continue explanation; Tubular mold 201 is held and makes mold hub 220 be approximate horizontal (shape); It is to have: cool off through 202 pairs of mold walls of circulation water coolant in mold cooling water chamber 204; And the heat of the cylindrical metal liquation 215 that is full of in the tubular mold 201 is captured from the face that contacts with the mold wall, thereby thereby form on this surface the tubular mold 201 of solidified shell the pressure cooling body, from cool water shower device 205 emit water coolant make the terminal water coolant of the outlet side of tubular mold 201 with solidify ingot casting 216 directly touching make the tubular mold 201 of the pressure cooling body that the cylindrical metal liquation 215 in the tubular mold 210 solidifies.And, tubular mold 201, the end with the ejiction opening opposition side of its cool water shower device 205 is connected with tundish 250 through refractory materials system tabular body 210.

In the 2nd figure, supply with the pressure refrigerative water coolant that is used for tubular mold 201, the pressure refrigerative water coolant that is used to solidify ingot casting 216 through water coolant supply-pipe 203, supply with water coolant dividually but also can distinguish.

Will from the extended line of the hub of the ejiction opening of cool water shower device 205 with cast solidify ingot casting 216 surperficial position contacting; Be called effective mould to the length of tubular mold 201 and the contact surface of refractory materials system tabular body 210 and grow (with reference to the symbol L of Fig. 4), be preferably 15mm～70mm.When this effective mould length during less than 15mm, can not form good epithelium etc., therefore become and can not cast; When surpassing 70mm, do not force the refrigerative effect, overriding by the solidify out into that the mold wall causes; Tubular mold 201 and cylindrical metal liquation 215 or become big with the drag that contacts of solidified shell, cast(ing) surface cracks, or in 201 internal fractures of tubular mold etc.; It is unstable that casting becomes, therefore not preferred.

The material of tubular mold 201, the one or more kinds of combinations of preferably selecting among aluminium, copper or their alloy.From heat conductivity, thermotolerance, physical strength aspect, can select the combination of material.

And then, preferably loaded the mold of perviousness porous matter material 222 with self lubricity with ring-type at the face that contacts with cylindrical metal liquation 215 of tubular mold 201.So-called ring-type is the state that is installed on circumferential direction all of inner-wall surface 221 of tubular mold 201.The venting quality of perviousness porous matter material 222 is preferably 0.005 (L (liter)/(cm ²/ minute))～0.03 (L/ (cm ²/ minute)), 0.07 (L/ (cm more preferably ²/ minute))～0.02 (L/ (cm ²/ minute)).The thickness of the perviousness porous matter material of installing 222 is not special to be limited, but is preferably 2mm～10mm, more preferably 3mm～8mm.As perviousness porous matter material 222, for example, can use venting quality is 0.008 (L/ (cm ²/ minute))～0.012 (L/ (cm ²/ minute)) graphite.At this, so-called venting quality is that to measure pressure for the test film of 5mm thickness be 2kg/cm ²The air flow of PM of air obtain.

5mm～the 15mm of preferred use among effective mould is long is equipped with the tubular mold 201 of perviousness porous matter material 222.Preferably at the interface configurations O type ring 213 of tubular mold 201, refractory materials system tabular body 210, perviousness porous matter material 222.

The shape of the inner-wall surface 221 in the radial direction cross section of tubular mold 201 except circle, can also be the shape that has trilateral, rectangular cross sectional shape or do not have the special crosssection shape of the symmetry axis or the plane of symmetry.Perhaps, in the occasion that molds the hollow ingot casting, can be the shape that maintains core in mold inside.In addition; Tubular mold 201 is molds of the tubular of both ends open; Alloy liquation 255 is via the spout that penetratingly is arranged at refractory materials system tabular body 210 (sprue gate) 211, gets into from the inside of an end to tubular mold 201, extrudes or pulls out from the other end and solidify ingot casting 216.

The inner-wall surface 221 of tubular mold 201, towards the pull-out direction that solidifies ingot casting 216,0 degree～3 is spent, more preferably the elevation angle of 0 degree～1 degree forms to constitute with mold hub 220.When the elevation angle is spent less than 0; Solidifying ingot casting 216 when tubular mold 201 is pulled out, receiving resistance in the outlet of tubular mold 201, therefore casting becomes impossible; And when the elevation angle is spent above 3; The inner-wall surface 221 of tubular mold 201 becomes insufficient with contacting of cylindrical metal liquation 215, reduces to the heat extraction effect of tubular mold 201 from cylindrical metal liquation 215 or solidified shell, solidifies thus to become insufficient.Its result produces fused surface again on the surface of solidifying ingot casting 216, the possibility that causes casting fault that perhaps sprays not solidified alloy liquation 255 grades from the end of tubular mold 201 increases, and is therefore not preferred.

Tundish 250 by accept to adopt outside smelting furnace etc. be adjusted to regulation alloying constituent molten aluminium alloy molten metal inflow portion 251, liquation maintaining part 252, constitute to the outflow portion 253 of tubular mold 201.Tundish 250 maintains the liquid level face 254 of alloy liquation 255 than position high above the tubular mold 201, and casts the occasion of (multiple casting) together in multimode, stably divides gold conjugate liquation 255 to each tubular mold 201.Remain in the alloy liquation 255 of the liquation maintaining part 252 in the tundish 250, be injected into the tubular mold 201 from the spout 211 that is arranged at refractory materials system tabular body 210.

Refractory materials system tabular body 210; Be to be used for member that tundish 250 and tubular mold 201 are separated; Can use the member of material with fireproof heat-insulating property; For example, can enumerate Le ミボ one De of (strain) ニチアス system, the イ Application シュラ Le of Off オセコ (strain) system, Off アイバ one Block ラ Application ケ Star トボ one De of イ PVC デ Application (strain) system.Refractory materials system tabular body 210 has the shape that can form spout 211.Spout 211 can form one or more at refractory materials system tabular body 210 from the part that the inner-wall surface 221 of tubular mold 201 stretches out to the inside.

Symbol 208 is to supply with the fluidic fluid supply line.As fluid, can enumerate lubricating fluid.Fluid can be any or the two or more fluids of from gas, liquid lubricant, selecting.The supply-pipe of gas, preferred liquid lubricant is provided with dividually.

From the fluid of fluid supply line 208 forced feeds, be supplied to the gap between tubular mold 201 and the refractory materials system tabular body 210 through annulus 224.Preferably form the gap below the 200 μ m at the position that tubular mold 201 and refractory materials system tabular body 210 are faced.This gap is that alloy liquation 255 does not have the degree that gets into, for fluid can be to the size of the inner-wall surface 221 effusive degree of tubular mold 201.In form shown in Figure 2; Annulus 224 runs through setting opposed to each other with the periphery side that is installed on the perviousness porous matter material 222 of tubular mold 201; Fluid is according to the internal penetration of institute's applied pressure to perviousness porous matter material 222; Be sent to whole of the perviousness porous matter material 222 that contacts with column alloy liquation 215, be supplied to the inner-wall surface 221 of tubular mold 201.Also there is liquid lubricant to be heated, becomes dissolving gas, be supplied to the situation of the inner-wall surface 221 of tubular mold 201.

Its result can make lubricated good between perviousness porous matter face, cylindrical metal liquation 215 peripherys and the solidified shell periphery of tubular mold 201.Through perviousness porous matter material 222 is installed with ring-type, can obtain more good lubricating effect, easily y alloy y continuous casting rod.

Utilization is selected from institute's gas supplied, liquid lubricant, liquid lubricant and decomposes a kind of or two or more among the gas that forms, can form space, bight 230.

Casting process for comprising in the method for manufacture of the present invention describes.

In the 2nd figure, the alloy liquation 255 in the tundish 250 via refractory materials system tabular body 210, is supplied to and remains mold hub 220 and be the tubular mold 201 of approximate horizontal, is forced cooling in the outlet of tubular mold 201, becomes and solidifies ingot casting 216.Solidify ingot casting 216 and utilize near the drive unit of outlet that is arranged at tubular mold 201 to be drawn out with certain speed, therefore casting serially becomes cast rod.The cast rod that is drawn out is cut to the length of regulation by synchronization cutting mechanism.That is, continuous casting rod, to adopt continuous metal cast process to make casting speed be 300 (mm/ minute)～2000 (mm/ minute) with the duraluminum The of medial temperature position liquidus line+40 ℃～liquidus line+230 of alloy liquation 255 ℃, cast and obtain.When being this condition and range, the fine dispersion of crystallisate becomes the molding of forging and molding property excellence and high-temperature machinery excellent strength.The occasion of continuous metal cast process, vertical continuous casting method, DC casting on hot top is preferably the casting speed of 80 (mm/ minute)～400 (mm/ minute).Therefore, casting speed is preferably 80 (mm/ minute)～2000 (mm/ minute).

Composition to the alloy liquation 255 that stores the duraluminum in tundish 250 describes.

Alloy liquation 255 is the Si that contains 10.5 quality %～13.5 quality % (being preferably 11.5 quality %～13 quality %), the Cu of 2.5 quality %～6 quality % (being preferably 3.5 quality %～5.5 quality %), the Mg of 0.3 quality %～1.5 quality % (being preferably 0.5 quality %～1.3 quality %), the Ni of 0.8 quality %～4 quality % (being preferably 1.8 quality %～3.5 quality %); And satisfy Ni (quality %) >=(0.68 * Cu (quality %)+AA (quality %)) (wherein; AA is a constant; AA >=4.2 are preferably AA >=4.7) the duraluminum of relational expression.

This alloy liquation 255 preferably contains among the Ti of V, 0.01 quality %～0.2 quality % (being preferably 0.02 quality %～0.1 quality %) of Zr, the 0.01 quality %～0.15 quality % (being preferably 0.05 quality %～0.1 quality %) of Cr, the 0.04 quality %～0.3 quality % (being preferably 0.1 quality %～0.2 quality %) of Mn, the 0.05 quality %～0.5 quality % (being preferably 0.1 quality %～0.3 quality %) of 0.1 quality %～1 quality % (being preferably 0.2 quality %～0.5 quality %) one or more.

And then, preferably contain the Fe of 0.15 quality %～0.65 quality % (being preferably 0.3 quality %～0.5 quality %).

In addition, the P that preferably contains 0.003 quality %～0.02 quality % (being preferably 0.007 quality %～0.016 quality %).

In addition; When containing a kind of or two or more among the Ca of Na, 0.001 quality %～0.02 quality % (being preferably 0.005 quality %～0.01 quality %) of Sb, the 0.0005 quality %～0.015 quality % (being preferably 0.001 quality %～0.01 quality %) of Sr, the 0.1 quality %～0.35 quality % (being preferably 0.15 quality %～0.25 quality %) of 0.003 quality %～0.03 quality % (being preferably 0.01 quality %～0.02 quality %); Have effect with eutectic Si miniaturization, therefore preferred.

Store the alloy liquation 255 in tundish 250 liquid level face 254 height and tubular mold 201 inner-wall surface 221 above the difference of height confirm as 0mm～250mm, 50mm～170mm more preferably.Poor through both are had, the gas that the pressure that is supplied to the alloy liquation 255 in the cartridge type mold 201 and lubricating oil and lubricating oil gasification form is balance well, so castibility is stable, and it is excellent easily to make the duraluminum continuous casting.Horizontal plane sensor (the level sensor that the height of the liquid level face 254 through will being used to measure alloy liquation 255 is monitored; Level sensor) be arranged in the tundish 250, precision manages well that this is poor, can maintain the value of regulation.

Liquid lubricant can use the vegetables oil as lubricating oil.For example, can enumerate rape oil, Viscotrol C, salad oil.They are little to the detrimentally affect of environment, and are therefore preferred.

The lubricating oil feed rate is preferably 0.05 (mL/ minute)～5 (mL/ minute) (0.1 (mL/ minute)～1 (mL/ minute) more preferably).When feed rate is very few, because lack of lubrication, the leakage (breakout) of ingot casting takes place, and feed rate is when too much, remainder is sneaked in the ingot casting, the homogeneity that might hinder size of microcrystal to distribute.

As the casting speed of pulling out the speed of solidifying ingot casting 216 from tubular mold 201, be preferably 300 (mm/ minute)～2000 (mm/ minute) (600 (mm/ minute)～2000 (mm/ minute) more preferably).Because the reticulattion of the crystallisate that forms through casting becomes evenly fine, the drag to the distortion of aluminum substrate at high temperature increases, and high-temperature machinery intensity improves, and is therefore preferred.Much less, action effect of the present invention is not cast speed and limits, but when accelerating casting speed, it is remarkable that its effect becomes.

From the cooling water inflow that cool water shower device 205 is emitted, each mold is preferably 5 (L/ minute)～30 (L/ minute) (25 (L/ minute)～30 (L/ minute) more preferably).When cooling water inflow is very few, leakage (breakout) takes place, or fusion again takes place in the surface of solidifying ingot casting 216, form uneven tissue, the homogeneity that might hinder size of microcrystal to distribute.On the other hand, when cooling water inflow was too much, the heat extraction of tubular mold 201 was excessive, became and can not cast.Much less, the action effect of the present invention water yield that is not cooled limits, but increase cooling power, when increasing from the freezing interface thermograde in tubular mold 201, it is remarkable that its effect becomes.

The medial temperature of the alloy liquation 255 that flows into to tubular mold 201 in the tundish 250 is preferably liquidus line+40 ℃～liquidus line+230 ℃ (more preferably liquidus line+60 ℃～liquidus line+200 ℃).The temperature of alloy liquation 255 is crossed when hanging down, and in tubular mold 201 and before it, forms thick crystallisate, the homogeneity that might hinder size of microcrystal to distribute.On the other hand, when the temperature of alloy liquation 255 was too high, a large amount of hydrogen got in the alloy liquation 255, got into as pore and solidified in the ingot casting 216 homogeneity that might hinder size of microcrystal to distribute.

In the present invention; These casting condition Be Controlled; The eutectic Si and the intermetallic compound base of the tissue of feasible casting article are not originally assembled balling; Therefore the aggregate of the reticulattion of the crystallisate that forms during for continuous casting or needle crystal thing or crystallisate, after this each heat treated effect can effectively be brought into play, and is therefore preferred.

In the present invention, the cast rod after the casting, put in the forging and molding operation as the base material before, as preceding thermal treatment ,-10 ℃～480 ℃ (being preferably-10 ℃～370 ℃) keep 2 hours～6 hours very important.Though more preferably temperature condition is a room temperature,, also can obtain its effect even below the room temperature.

When thermal treatment is above-mentioned preceding thermal treatment before make; Just become in tissue, the aggregate of the reticulattion of the crystallisate that forms during continuous casting or needle crystal thing or crystallisate is also partly residual aluminium molding after shaping and thermal treatment, the crystallisate of these shapes; The drag to the distortion of aluminum substrate as at high temperature plays a role; Even its result during 250 ℃～400 ℃ high temperature, also can obtain excellent physical strength.That is, under aluminum substrate remollescent high temperature, the aggregate of the reticulattion of crystallisate or needle crystal thing or crystallisate becomes the drag to distortion, therefore becomes the aluminium molding of high-temperature machinery excellent strength.On the other hand, current thermal treatment temp is high, when shaping rate is high, and the aggregate of the reticulattion of crystallisate or needle crystal thing or crystallisate is blocked, and with granular gathering, becomes crystallisate and is scattered in the state in the remollescent aluminum substrate at high temperature equably.Therefore, crystallisate at high temperature reduces to the drag of the distortion of aluminum substrate, and high-temperature machinery intensity can not improve.

The present invention is under above-mentioned alloy composition; Through 250 ℃～400 ℃ more high-temperature zone softening at aluminum substrate, that be very easy to distortion; Make reticulattion, acicular structure, the aggregate of crystallisate of opposing aluminum substrate distortion partly residual, improve high-temperature machinery intensity.

As 6000 of the less lower concentration alloy of the crystallisate of the net that less can see crystallisate, acicular structure is alloy etc.; Suppressing or omitting under the situation about handling that homogenizes; It is sought to suppress recrystallize and simplifies working process, and the crystallisate as the present invention is many, the high Si that can see net, acicular structure when casting is an alloy, is to keep net, acicular structure as far as possible; Seek the alloy of pyritous improvement, both are different.

As described in the above-mentioned background technology hurdle; The content of patent documentation 1 (TOHKEMY 2002-294383 communique) institute's publicity is an alloy about 6000; The treatment temperature that will homogenize suppresses or omits; Not in order to obtain hot properties, but, improve the mechanical characteristics of normal temperature in order to suppress recrystallize.Original alloy system is also different, is the fewer lower concentration alloy of crystallisate, less can see reticulattion, the acicular structure of crystallisate.Be to handle low temperatureization through homogenizing to suppress, make the Al-Mn system that suppresses recrystallize, the alloy that the Al-Cr based compound is separated out imperceptibly.Crystallisate as the present invention high Si many, that can see reticulattion, acicular structure when casting are alloy, are to keep reticulattion, acicular structure as far as possible, seek the alloy of high-temperature upgraded, and both are different.

Particularly in the high-temperature machinery intensity that improves the base material, improve the occasion of forging property, preceding heat treated maintenance temperature is preferably 200 ℃～370 ℃.When being this TR; Before eutectic Si, the gathering balling of intermetallic compound during thermal treatment be difficult to carry out; The aggregate of the reticulattion of the crystallisate that forms during continuous casting or needle crystal thing or crystallisate is also partly remaining after forging and molding, post-heat-treated, becomes the aluminium molding of high-temperature machinery excellent strength.

In addition, particularly in the occasion that further improves the high-temperature machinery intensity of base material, preceding heat treated maintenance temperature is preferably-10 ℃～200 ℃.When being this TR; Before eutectic Si, intermetallic compound base during thermal treatment originally do not assemble balling; The aggregate of the reticulattion of the crystallisate that forms during continuous casting or needle crystal thing or crystallisate is also partly remaining after forging and molding, post-heat-treated, becomes the aluminium molding of high-temperature machinery excellent strength.

And in the occasion that further improves the forging and molding property of base material, preceding heat treated maintenance temperature is preferably 370 ℃～480 ℃.When being this TR, eutectic Si, intermetallic compound during preceding thermal treatment are assembled balling to a certain degree, and the resistance to deformation during casting reduces, and therefore become the excellent aluminium molding of forging and molding property.And when being this TR, the reticulattion of the crystallisate that forms when forging continuously or the aggregate of needle crystal thing or crystallisate are also partly remaining after forging and molding, post-heat-treated, can obtain the excellent aluminium molding of high-temperature machinery character.

Before heat treatment step, as long as be arranged at from casting the back to the forging process, for example, as long as casting one day after with interiorly handle, perhaps a back week of processing with the interior forging process of putting into.Can implement correction process, peeling processing therebetween.

Then, the example to the forging process that comprises among the present invention describes.Method of manufacture of the present invention comprises: the operation that 1) the continuous casting pole is cut to the length of regulation; 2) the base material that cuts off is preheated, carry out the operation of upsetting; 3) operation that the base material of upsetting is lubricated; 4) the base material is put in the mould, carried out the operation of forging and molding; 5) utilize the demoulding (liftout; Knock-out) mechanism's operation that forged article is discharged in the mould.

Also can be to forging stock material application of lubricating, heating before dropping into the upsetting processing again.In addition, can omit the upsetting operation.

Lubricant is handled, and can be the coating or the bonderizing of soluble oil.For example, preferably after the base material is implemented bonderizing, be heated to 380 ℃～480 ℃, put in the forging apparatus again as preheating.When preheating to 380 ℃～480 ℃, the energy of deformation of base material improves, and is configured as complicated shape and becomes easy.

As lubricant, preferred water-based lubricant more preferably uses water-soluble oildag.Reason is that the better underground heat of graphite sticks at the base material.In this case, for example,, the base material is cooled to (after for example keeping 2 hours～4 hours) behind the normal temperature, the base material is heated to 380 ℃～480 ℃, put in the forging apparatus more preferably to behind 70 ℃～350 ℃ the base material application of lubricating.As lubricant, preferred water-based lubricant more preferably uses water-soluble oildag.Reason is that the better underground heat of graphite sticks at the base material.

Before with base material input, to the die surface application of lubricating.Amounts of lubrication, can reach more suitable state corresponding to the combination of patrix and die (dies) at the winding-up time through adjustment spraying (spray).As lubricant, preferably use oily lubricant.For example, can use MO.Reason is can suppress die temperature to descend, and die temperature descends sometimes when being aqueous lubricating oil.When oily lubricant was the mixture of graphite and MO, lubricant effect improved, and was preferred therefore.

The Heating temperature of mould is preferably 150 ℃～250 ℃.Reason is to obtain sufficient plastic flow.

In the present invention, the working modulus at the position that requires high temperature resistant fatigue strength in the forging and molding is preferably (more preferably below 70%) below 90%.When being this working modulus when following, can suppress the blocking of aggregate of reticulattion or the needle crystal thing or the crystallisate of crystallisate, become the molding of high-temperature machinery excellent strength.

In addition, as long as in molding, require the position of high-temperature machinery intensity to satisfy this working modulus.

In addition, before forging, implemented the occasion of the plastic working of upsetting operation etc., preferred working modulus is considered as their total amount.For example, under the situation for molding with complicated shape, the preferred working modulus of processing each time is 10%～80% (more preferably 10%～50%), and processing repeatedly (is preferably 2 times).For example, preferred primary working modulus is 10%～50% (more preferably 10%～30%).

At this, so-called working modulus, definition is as follows.

Working modulus=(thickness after the thickness-plastic working before the plastic working)/(thickness before the plastic working) * 100%

Goods to having forged are implemented post-heat-treated.As post-heat-treated, can solution treatment, ageing treatment combination be used.Post-heat-treated can be carried out with interior in a back week of processing.

Specifically, for example, the goods that can under 3 hours condition of 480 ℃～520 ℃ (being preferably 490 ℃～510 ℃) maintenance, will forge carry out solution treatment.

As the post-heat-treated beyond above-mentioned, can implement the T5 thermal treatment or the T6 thermal treatment of JIS standard to the goods that forged.

In the present invention, preferably the forged article that takes out is not implemented solutionizing, quenching and kept 1 hour～10 hours 170 ℃～230 ℃ (being preferably 190 ℃～220 ℃) as ageing treatment.Can suppress the blocking, assemble of aggregate of crystallisate net or needle crystal thing or crystallisate, become the molding of high-temperature machinery excellent strength, be preferred therefore.

The alloy structure of the molding of making by such method; The gathering balling of eutectic Si, intermetallic compound is difficult to carry out; The reticulattion of the crystallisate that continuous casting forms or the aggregate of needle crystal thing or crystallisate are also partly remaining after forging and molding, post-heat-treated, become the aluminium molding of high-temperature machinery excellent strength.

In addition; Alloy composition is the Si that contains 10.5 quality %～13.5 quality % (being preferably 11.5 quality %～13 quality %), the Cu of 2.5 quality %～6 quality % (being preferably 3.5 quality %～5.5 quality %), the Mg of 0.3 quality %～1.5 quality % (being preferably 0.5 quality %～1.3 quality %), the Ni of 0.8 quality %～4 quality % (being preferably 1.8 quality %～3.5 quality %); And satisfy Ni (quality %) >=(0.68 * Cu (quality %)+AA (quality %)) (wherein; AA is a constant; AA >=4.2 are preferably AA >=4.7) the duraluminum of relational expression.

Preferred alloy is formed the Mn that contains 0.1 quality %～1 quality % (being preferably 0.2 quality %～0.5 quality %); 0.05 the Cr of quality %～0.5 quality % (being preferably 0.1 quality %～0.3 quality %); 0.04 the Zr of quality %～0.3 quality % (being preferably 0.1 quality %～0.2 quality %); 0.01 the V of quality %～0.15 quality % (being preferably 0.05 quality %～0.1 quality %); 0.01 one or more among the Ti of quality %～0.2 quality % (being preferably 0.02 quality %～0.1 quality %).

In addition; When among the Ca of the Na of the Sb of the Sr that contains 0.003 quality %～0.03 quality % (being preferably 0.01 quality %～0.02 quality %), 0.1 quality %～0.35 quality % (being preferably 0.15 quality %～0.25 quality %), 0.0005 quality %～0.015 quality % (being preferably 0.001 quality %～0.01 quality %), 0.001 quality %～0.02 quality % (being preferably 0.005 quality %～0.01 quality %) one or more; Have effect with eutectic Si miniaturization, therefore preferred.

(embodiment)

Below through embodiment the present invention is described particularly, but the present invention is not limited by these embodiment.

(embodiment 1～16)

(creating conditions)

Adopt the production system shown in the 1st figure, produce the duraluminum molding of the comparative example 1～10 shown in embodiment 1～16 shown in the table 1 and the table 2.

As the casting apparatus 81 that constitutes this production system, use the hot top continuous caster shown in the 5th figure, cast out the continuous casting pole of 85 Φ (mm) of the duraluminum of embodiment 1～16 with the composition shown in the table 1 and the comparative example 1～10 shown in the table 2 respectively.Above-mentioned hot top continuous caster is the casting machine that adopts the hot top of gas pressurization casting; Be constituted as to the gap of end plate and mold and import gas and lubricating oil, the gas that makes the pressure that is supplied to the alloy liquation in the mold and lubricating oil and lubricating oil gasify to form is balance well.Constitute according to this, the regional stenosis that aluminum melt contacts with mold is narrow, therefore can utilize water coolant to carry out quench solidification the alloy liquation, stably y alloy y continuous casting rod.

Then, as preceding heat treatment step, to the processing that under the temperature shown in table 1 and the table 2, homogenizes of each continuous casting pole.Each continuous casting pole is cut to the thickness of 20mm or 80mm, forms the forging stock material.Then, this forging stock material is preheated after 420 ℃, carry out the upsetting operation with the upsetting working modulus of the regulation shown in table 1 and the table 2, plastic working becomes the shape of regulation.

In addition, for embodiment 5～7,10～13, estimated the upsetting working modulus and be the cracking frequency under 55% the situation.This evaluation result is shown in table 3.In table 3, the cracking frequency that zero symbol and △ symbolic representation are caused by the upsetting operation is respectively less than more than 1% and 1%.

Table 3

Then,, carry out the post-heat-treated operation of the regulation shown in table 1 and the table 2, produce above-mentioned each embodiment and above-mentioned each comparative example respectively for the above-mentioned base material of plastic working.

In addition; Above-mentioned post-heat-treated operation is through plastically worked article is carried out water quenching, 210 ℃ of T5 thermal treatments that keep 6 hours down; Perhaps plastically worked article is carried out water quenching after keeping 2.5 hours under 500 ℃, handle at 210 ℃ of heat treated each of T6 that kept 6 hours down and carry out.

(fatigue strength evaluation)

For above-mentioned each embodiment and each comparative example, adopt following method to estimate fatigue strength.

Make test film from each embodiment and each comparative example through mechanical workout; Utilize little wild formula rotating bending fatigue machine; To test film after 300 ℃ or 350 ℃ are implemented 100 hours preheating down, under each environment of 300 ℃ and 350 ℃, test film is estimated fatigue strength.Give 1,000 ten thousand times pulsating stress, measure damaged stress does not take place.

Composition in each embodiment and each comparative example, heat-treat condition, upsetting working modulus, fatigue strength evaluation result and the constant A A that satisfies by the relational expression of Ni (quality %)=(0.68 * Cu (quality %)+AA (quality %)) definition are shown in table 1 and table 2.In addition, the relation of the containing ratio of Ni in the composition of each embodiment and each comparative example and Cu is shown in the 6th figure.In addition, in the 6th figure, each AA value of embodiment 1～14 is respectively by S1～S14 symbolic representation, and each AA value of comparative example 1～10 (except the comparative example 6) is respectively by C1～C10 symbolic representation.

Embodiment 1～16 adopts method of manufacture of the present invention to make, and can be known under 350 ℃, to have the fatigue strength more than the 33MPa by table 1.Like this, the embodiment 1～16 that adopts method of manufacture of the present invention to make all is the fatigue strength with target, the parts of the physical strength in the time of therefore can performing well in requiring high temperature.

The duraluminum that in method of manufacture of the present invention, uses, must be the content of Ni and Cu be included among the 6th figure by forming in the A-B-C-D-E-A area surrounded.

The content of Ni and Cu is included in by the embodiment in the D-E-H-I-D area surrounded 6, embodiment 10～13, and is as shown in table 3, all can come to process well with the upsetting working modulus above 55%.Like this, in the present invention, the content that more preferably uses Ni is below the 2.0 weight %, contain Cu makes the duraluminum of AA >=4.2.

Relative therewith, have in method of manufacture of the present invention the comparative example 1～5,7～10 of the composition outside the alloy composition scope of confirming, as shown in table 2, the fatigue strength that does not all have target.Comparative example 8 and 10, and then plastic working property is relatively poor, and crackle takes place during upsetting." * 1 " expression shown in the table 2 can not be produced the test film of comparative example.In addition, the AA value of comparative example 1～4 is less than 4.2.In addition, the comparative example 6 of preceding heat treatment step, the fatigue strength that does not also have target have been implemented with the temperature outside the TR of in method of manufacture of the present invention, confirming.

(evaluation of metal structure)

Cut the structure observation sample from the vertical section central part of each comparative example of each embodiment of table 1 and table 2, carry out microcosmic and grind,, estimate the metal structure of each embodiment and each comparative example thus by the reticulattion that Photomicrograph is observed crystallisate.

In the tissue of embodiment, the aggregate of the reticulattion of the crystallisate that forms in the time of can confirming continuous casting or needle crystal thing or crystallisate is also partly residual after shaping and thermal treatment.

In addition; In an embodiment, the area ratio/occupancy ratio of eutectic Si is more than 8%, and the median size of eutectic Si is below the 5 μ m; Needle-like is than being that eutectic Si more than 1.4 is more than 25%; The area ratio/occupancy ratio of intermetallic compound is more than 1.2%, and the median size of intermetallic compound is more than the 1.5 μ m, and length is that 3 μ m aggregate above, intermetallic compound or contacted intermetallic compound is more than 30%.

The embodiment 10 and 13 that particularly contains Ni and Cu with above-mentioned preferred concentrations; As shown in table 4ly know; The median size that all is eutectic Si is below the 2.5 μ m; Have needle-like about 80% than being the eutectic Si more than 1.4, the length that has about 90% is 3 μ m aggregates above, intermetallic compound.

In addition; Result according to table 1 and table 4 can know, constant A A is greater than 4.7 embodiment 13, with constant A A less than 4.7 embodiment 10 relatively; Help the generating capacity of netted or acicular intermetallic compound of hot strength more, fatigue strength is greater than the fatigue strength of embodiment 10.Like this, in the present invention, preferably being modulated into constant A A is the duraluminum molding more than 4.7.

Relative therewith, above-mentioned each comparative example, its needle-like is littler than embodiment than the length of aggregate of length or contacted intermetallic compound of containing ratio, intermetallic compound that is the eutectic Si more than 1.4.For example, as shown in table 4,6 of comparative examples have needle-like about 22% than being the eutectic Si more than 1.4, only have length about 28% and be 3 μ m aggregate above, intermetallic compound or contacted intermetallic compound.

Table 4

(embodiment 17,18)

(creating conditions)

At the composition shown in the table 5 and under creating conditions, adopt with embodiment 1～16 and comparative example 1～10 same method of manufacture and produce embodiment 17,18 and comparative example 11,12 respectively.In addition, comparative example 13 is by pulverous extrusion casting material forming, and the continuous casting pole by duraluminum is not shaped, and processings that do not homogenize adopted and comparative example 11 and 12 same method of manufacture manufacturings in addition.Embodiment 17,18 and comparative example 11～13, all as the 7th figure (a)～(c) shown in, be configured as have diameter 80mm is arranged, the duraluminum molding of the shape of the piston 1 of the crown 10 of thickness 8mm.

(fatigue strength evaluation)

For embodiment 17,18 and comparative example 11～13, adopt following method to estimate fatigue strength.

At first, for the piston 1 of each embodiment and each comparative example, after 300 ℃ or 350 ℃ are implemented 100 hours preheating down, cut test film 11 from the central part of the crown 10 of each embodiment and each comparative example.Under each temperature environment corresponding,, each test film 11 is estimated fatigue strength through the pulsation tensile fatigue test with above-mentioned pre-heating temperature.In above-mentioned fatigue test, set stress ratio R=-0.1, will be through 1,000 ten thousand times and not the maximum stress of fracture as fatigue strength.The fatigue strength evaluation result of embodiment 17,18 and comparative example 11～13 is shown in table 5.

Can know that by table 5 fatigue strength of embodiment 17,18 under 350 ℃ surpassed preferred 43MPa in the parts of the physical strength when requiring high temperature, and the fatigue strength 300 ℃ under is above 55MPa.In addition, embodiment 17 and 18, except shape, the identical embodiment that creates conditions 10 and 13 is corresponding with having used, and can know not according to evaluation method, when high temperature, has steady

Fixed physical strength.

Relative therewith, comparative example 11, its AA value is less than 4.2, and except shape, the identical comparative example of creating conditions 2 is corresponding with having used.Fatigue strength evaluation result by the comparative example 11 of the comparative example 2 of table 2 and table 5 can be thought the safety of the physical strength when comparative example 11 lacks high temperature.

In addition, the AA=1.68 of comparative example 12, the fatigue strength under 350 ℃ is markedly inferior to 43MPa.

In addition, by the comparative example 13 of pulverous extrusion casting material forming, although AA=1.7 has the fatigue strength higher than embodiment 17,18, the shortcoming that exists is the thin part of the formed article through pressing solidly, and for example skirt section 12 becomes fragile easily.Like this, used the molding of pulverous extrusion casting material, compared as the duraluminum molding of the forging and molding operation of base material by the continuous casting rod that duraluminum forms with having use, ductility and toughness are relatively poor.

The duraluminum molding that adopts method of manufacture of the present invention to make, ductility, toughness and fatigue strength are excellent, can perform well in the crown position of internal combustion engine etc.

Utilize possibility on the industry

As described above; The present invention has continuous casting rod that use forms by the duraluminum method of manufacture as the duraluminum molding of the forging and molding operation of base material; Above-mentioned duraluminum contains Si, Cu, Mg and Ni; Therefore according to the present invention, can obtain high temperature fatigue intensity and forging property, ductility, the good molding of toughness.In addition, Ni and Cu satisfy the relational expression of Ni (quality %) >=(0.68 * Cu (quality %)+4.2 (quality %)), and the fatigue strength characteristic under the higher temperature is improved.

The duraluminum molding of the application of the invention, comparable internal combustion engine in the past is thin-walled property more, can realize the lightweight of internal combustion engine.In addition, can tackle the desired lightweight in market, can realize that the burnup of oil engine reduces, go out the activity of force raising.

Among the present invention the expression numerical range " more than " and " following " include given figure.

Claims

1. the method for manufacture of a duraluminum molding, it has continuous casting rod that use forms by the duraluminum forging and molding operation as the base material, it is characterized in that,

Duraluminum contains the Si of 10.5 quality %～13.5 quality %, the Cu of 2.5 quality %～6 quality %, the Mg of 0.3 quality %～1.5 quality %, the Fe of 0.15 quality %～0.5 quality % and the Ni of 0.8 quality %～4 quality %; And satisfy the relational expression of Ni (quality %) >=(0.68 * Cu (quality %)+4.7 (quality %))

This method of manufacture comprises thermal treatment and heating process, and said thermal treatment and heating process comprise and preheat operation before preceding heat treatment step to the base material, the forging processing to the base material and to the post-heat-treated operation of duraluminum molding,

Preceding heat treatment step is included in-10 ℃～480 ℃ processing that keep 2 hours～6 hours.

2. the method for manufacture of duraluminum molding according to claim 1, wherein, the thermal treatment temp of preceding heat treatment step is 200 ℃～370 ℃.

3. the method for manufacture of duraluminum molding according to claim 1, wherein, the thermal treatment temp of preceding heat treatment step is-10 ℃～200 ℃.

4. the method for manufacture of duraluminum molding according to claim 1, wherein, the thermal treatment temp of preceding heat treatment step is 370 ℃～480 ℃.

5. according to the method for manufacture of each described duraluminum molding of claim 1～4, wherein, the post-heat-treated operation is not implement solution treatment and kept 1 hour～10 hours at 170 ℃～230 ℃.

6. the method for manufacture of duraluminum molding according to claim 1, duraluminum contain the Fe of 0.3 quality %～0.5 quality %.

7. the method for manufacture of duraluminum molding according to claim 1, duraluminum contain the P of 0.003 quality %～0.02 quality %.

8. the method for manufacture of duraluminum molding according to claim 1, duraluminum contain any or the two or more combinations among the Ca of Na, 0.001 quality %～0.02 quality % of Sb, the 0.0005 quality %～0.015 quality % of Sr, the 0.1 quality %～0.35 quality % of 0.003 quality %～0.03 quality %.

9. the method for manufacture of duraluminum molding according to claim 1, duraluminum contain any or the two or more combinations among the Ti of V, 0.01 quality %～0.2 quality % of Zr, the 0.01 quality %～0.15 quality % of Cr, the 0.04 quality %～0.3 quality % of Mn, the 0.05 quality %～0.5 quality % of 0.1 quality %～1.0 quality %.

10. the method for manufacture of duraluminum molding according to claim 1, the working modulus at the position that requires high temperature resistant fatigue strength in the forging and molding operation is below 90%.

11. pre-heating temperature is 380 ℃～480 ℃ before the method for manufacture of duraluminum molding according to claim 1, the processing in the forging and molding operation.

12. it be 80mm/ minute～2000mm/ minute to the medial temperature of liquation is that the duraluminum of liquidus line+40 ℃～liquidus line+230 ℃ is cast and obtained that the method for manufacture of duraluminum molding according to claim 1, continuous casting rod adopt continuous metal cast process to make casting speed.

13. duraluminum molding; It is the duraluminum molding that adopts each described method of manufacture manufacturing of claim 1～12; It is characterized in that; In tissue, the aggregate of the reticulattion of the crystallisate that forms during continuous casting or needle crystal thing or crystallisate is also partly residual after shaping and thermal treatment.

14. duraluminum molding; It is the duraluminum molding that adopts each described method of manufacture manufacturing of claim 1～12; It is characterized in that the area ratio/occupancy ratio of eutectic Si is more than 8%, the median size of eutectic Si is below the 5 μ m; Needle-like is than being that eutectic Si more than 1.4 is more than 25%; The area ratio/occupancy ratio of intermetallic compound is more than 1.2%, and the median size of intermetallic compound is more than the 1.5 μ m, and length is that 3 μ m aggregate above, intermetallic compound or contacted intermetallic compound is more than 30%.

15. according to claim 13 or 14 described duraluminum molding, it is the duraluminum system engine piston with crown position, skirt section, it is characterized in that, the high temperature fatigue intensity at said crown position is more than the 50MPa.

16. a production system is characterized in that, a series of operation from liquation to the duraluminum molding is constructed as continuous lines, in its operation, comprises the operation of method of manufacture of each described duraluminum molding of claim 1～12 at least.