CN115976384B - AlN/AE44 composite material with excellent high-temperature mechanical property and preparation method thereof - Google Patents
AlN/AE44 composite material with excellent high-temperature mechanical property and preparation method thereof Download PDFInfo
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- 239000002131 composite material Substances 0.000 title claims abstract description 92
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 239000000956 alloy Substances 0.000 claims abstract description 129
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 128
- 239000011777 magnesium Substances 0.000 claims abstract description 61
- 229910052749 magnesium Inorganic materials 0.000 claims abstract description 56
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims abstract description 54
- 239000002245 particle Substances 0.000 claims abstract description 52
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000011159 matrix material Substances 0.000 claims abstract description 16
- 239000006185 dispersion Substances 0.000 claims abstract description 11
- 238000010907 mechanical stirring Methods 0.000 claims abstract description 8
- 238000003723 Smelting Methods 0.000 claims abstract description 7
- 238000001132 ultrasonic dispersion Methods 0.000 claims abstract description 3
- 238000001125 extrusion Methods 0.000 claims description 18
- 229910052782 aluminium Inorganic materials 0.000 claims description 17
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 17
- 238000003756 stirring Methods 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 10
- DFIYZNMDLLCTMX-UHFFFAOYSA-N gadolinium magnesium Chemical compound [Mg].[Gd] DFIYZNMDLLCTMX-UHFFFAOYSA-N 0.000 claims description 9
- 238000004321 preservation Methods 0.000 claims description 7
- 238000005266 casting Methods 0.000 claims description 5
- 238000000265 homogenisation Methods 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 229910018503 SF6 Inorganic materials 0.000 claims description 2
- 238000007790 scraping Methods 0.000 claims description 2
- 238000007711 solidification Methods 0.000 claims description 2
- 230000008023 solidification Effects 0.000 claims description 2
- SFZCNBIFKDRMGX-UHFFFAOYSA-N sulfur hexafluoride Chemical compound FS(F)(F)(F)(F)F SFZCNBIFKDRMGX-UHFFFAOYSA-N 0.000 claims description 2
- 229960000909 sulfur hexafluoride Drugs 0.000 claims description 2
- 239000013078 crystal Substances 0.000 abstract description 16
- 230000008569 process Effects 0.000 abstract description 8
- 238000005728 strengthening Methods 0.000 abstract description 2
- 229910000861 Mg alloy Inorganic materials 0.000 description 13
- 229910052688 Gadolinium Inorganic materials 0.000 description 10
- 230000006872 improvement Effects 0.000 description 10
- 238000001192 hot extrusion Methods 0.000 description 8
- 238000009864 tensile test Methods 0.000 description 7
- 239000006104 solid solution Substances 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000011888 foil Substances 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 238000009827 uniform distribution Methods 0.000 description 3
- 229910000838 Al alloy Inorganic materials 0.000 description 2
- 238000010009 beating Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000010406 interfacial reaction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
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- 238000004806 packaging method and process Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000007123 defense Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
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- 239000008188 pellet Substances 0.000 description 1
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- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
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- 239000013585 weight reducing agent Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Abstract
The invention discloses an AlN/AE44 composite material with excellent high-temperature mechanical property, which comprises the following components in percentage by mass: magnesium base alloy: 99-99.8%, alN particles: 0.2% -1.0%; wherein the magnesium base alloy comprises RE:3.5-4.5%, al:3.5-4.5%, and the balance of Mg. The invention also provides a preparation method of the AlN/AE44 composite material with excellent high-temperature mechanical properties. Strengthening magnesium base alloy by adopting heat-resistant AlN particles, and simultaneously introducing mechanical stirring and ultrasonic dispersion in the smelting process to promote uniform dispersion of the AlN particles; the AlN particles and the magnesium matrix alloy react at the interface, so that the AlN particles are added, most of the spherulitic Al-RE second phase in the AE44 alloy is effectively promoted to be separated out, the second phase is uniformly dispersed in the crystal grains, dislocation movement in the crystal is effectively prevented in the alloy deformation process, the high-temperature performance of the alloy is obviously enhanced, and the high-temperature performance of the alloy is effectively improved.
Description
Technical Field
The invention belongs to the technical field of magnesium alloy matrix composite materials, and particularly relates to an AlN/AE44 composite material with excellent high-temperature mechanical properties and a preparation method thereof.
Background
Nowadays, automobiles are the main transportation means for people to travel, and magnesium alloy is the lightest alloy in the current metal structural materials, so that the magnesium alloy has high specific strength and specific rigidity and good vibration reduction performance. In the automotive field, magnesium alloy can greatly reduce the weight of objects to reduce energy consumption, so that the realization of weight reduction through magnesium alloy materials has become an important trend in the automotive industry. However, automotive parts are subjected to high temperatures for long periods of time during use. However, when the temperature exceeds 120 ℃, the strength of the magnesium alloy is obviously reduced, and the use requirement of the structural member at high temperature cannot be met, so that the heat resistance of the magnesium alloy needs to be improved.
The Mg-RE-Al alloy is a heat-resistant alloy system which is researched and applied at present, wherein the AE44 alloy not only has excellent high temperature resistance, but also has lower RE content requirement, and can greatly reduce the cost in industrial production and application, so that the RE-Al alloy is applied to the automobile industry at present. However, when the temperature is higher than 200 ℃, the second phase of the alloy can not effectively maintain the stability of the grain boundary, so that the tensile strength of the alloy is weaker, the application range of the alloy is greatly limited, and related processes need to be explored to regulate and control the structure of the AE44 (wherein AE44 is the generic name of Mg-4Al-4RE alloy) alloy and improve the high-temperature performance above 200 ℃.
At present, the heat resistance of the magnesium alloy can be improved by methods of forming magnesium-based composite materials by adding particles, heat treatment, hot extrusion and the like. The AlN particles not only have high-temperature resistance characteristics such as high melting point, high hardness, good thermal stability and the like, but also have a crystal configuration and a lattice parameter similar to those of Mg, and are reinforcing phases with great development potential in magnesium alloy. The effect of improving the heat resistance of the magnesium alloy by adding the particles can be realized by improving the uniform distribution of the particles in the crystal, and the formation and the distribution of the second phases in the alloy are regulated and controlled by the interface reaction of the particles and the matrix, so that the method is an important aspect for improving the performance of the alloy. Therefore, alN particles are introduced into the AE44 series alloy, and the regulation and control effect of the AlN particles on the second phase structure of the AE44 alloy is studied, so that the method has important significance in exploring the strengthening mode of the high-temperature performance of the magnesium alloy.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, the main purpose of the invention is to provide an AlN/AE44 composite material with excellent high-temperature-resistant mechanical property, and aims to solve the problem that the existing AE44 composite material is poor in high-temperature mechanical property. The invention also provides a preparation method of the AlN/AE44 composite material with excellent high-temperature-resistant mechanical property.
The invention aims at realizing the following technical scheme:
an AlN/AE44 composite material with excellent high-temperature mechanical property, wherein the composite material comprises the following components in percentage by mass: magnesium base alloy: 99-99.8%, alN particles: 0.2% -1.0%; wherein the magnesium base alloy comprises RE:3.5-4.5%, al 3.5-4.5% and Mg in balance.
In certain embodiments, the AlN particles have a particle size of 40-60nm.
The preparation method of the AlN/AE44 composite material with excellent high-temperature mechanical property comprises the following steps:
1) Smelting and ingot casting of the composite material: according to the formula requirement, adding AlN particles into a magnesium matrix alloy melt, and carrying out preliminary dispersion on the AlN particles by adopting mechanical stirring to obtain a composite melt; after the composite melt is heated to the liquidus temperature, further dispersing the composite melt by adopting ultrasonic waves, and after the dispersion is completed, carrying out heat preservation and standing, and then casting and forming to obtain an ingot;
2) And (3) carrying out homogenization heat treatment and extrusion molding on the cast ingot obtained in the step (1) to obtain the AlN/AE44 composite material with excellent high-temperature mechanical properties.
In certain embodiments, the magnesium base alloy melt is prepared by the steps of:
the volume ratio is 99: CO of 1 2 And SF (sulfur hexafluoride) 6 Under the protection of mixed gas, placing the pure magnesium ingot with the mass percentage into a resistance furnace, heating up to 730-750 ℃ along with the resistance furnace, and stirring uniformly after the pure magnesium ingot is completely melted to obtain a magnesium melt; then adding magnesium gadolinium intermediate alloy and pure aluminum ingot into magnesium melt, standing for 5-10min until the magnesium melt is completely melted, uniformly stirring, and scraping scum on the surface of the alloy melt to obtain the magnesium base alloy melt.
In certain embodiments, the AlN particles are added by reducing the temperature of the magnesium base alloy melt to 620-640 ℃, mechanically stirring at 100-500rpm, and stirring for 5-10min.
Further, adding the AlN particles into the magnesium base alloy melt, mechanically stirring uniformly to obtain a composite melt, heating the composite melt to 680-690 ℃, and dispersing the composite melt by adopting ultrasonic waves, wherein the frequency of the ultrasonic waves is 19.5-20.7kHz, and the dispersing time is 8-12min.
Further, after the composite melt is uniformly dispersed by ultrasonic waves, scum on the surface of the composite melt is scraped off, the temperature of the composite melt is reduced to 640-650 ℃, and after standing for 5-10min, the composite melt is cast into a metal mold for cooling and solidification.
In certain embodiments, the homogenization heat treatment is performed at a temperature of 520 ℃ for a period of 8 hours.
In certain embodiments, the extrusion conditions are: the extrusion temperature was 385 deg.c and the extrusion ratio was 10.
In some embodiments, the method further comprises preheating the pure magnesium ingot, magnesium gadolinium intermediate alloy and pure aluminum ingot during the preparation of the magnesium base alloy melt.
Compared with the prior art, the invention has at least the following advantages:
1) According to the AlN/AE44 composite material with excellent high-temperature-resistant mechanical property, heat-resistant AlN particles are adopted to strengthen magnesium base alloy, and mechanical stirring and ultrasonic dispersion are introduced in the smelting process to promote uniform dispersion of the AlN particles; meanwhile, due to the interfacial reaction of the AlN particles and the magnesium base alloy, the addition of the AlN particles can effectively promote the precipitation of most of the spherulitic second phase in the AE44 alloy, and the dispersion is kept uniformly distributed in the crystal grains, so that dislocation movement in the crystal grains in the alloy deformation process can be effectively prevented, and further the high-temperature performance of the alloy is obviously strengthened; and along with the increase of the AlN particle content, the second phase structure in the alloy is obviously increased, and the spherical second phase is uniformly dispersed in the crystal grains, so that the high-temperature performance of the alloy is effectively improved. In the as-cast state and the extrusion state, the yield strength and the tensile strength of the composite material at 250 ℃ are obviously higher than those of an AE44 matrix alloy: when the addition amount of AlN is 0.7 wt%, the yield strength of the alloy at 250 ℃ can be improved by 20-30 MPa, and the improvement amplitude can reach 31% -89%; the tensile strength can be improved by about 12MPa, the improvement range can reach 11% -13%, and the high-temperature tensile property is improved obviously, namely, the high-temperature property of the AE44 alloy can be improved greatly by introducing low-content AlN particles.
2) According to the preparation method of the AlN/AE44 composite material with excellent high-temperature-resistant mechanical property, provided by the invention, the mechanical property of the AE44 alloy at the high temperature of 250 ℃ is improved by adding AlN particles and carrying out heat treatment and hot extrusion, the method is simple and practical, the test parameters are convenient to control, the portability is strong, the content of rare earth elements (Gd) is low, the cost is low, and the added Al element accords with the alloy range of the common high-strength magnesium alloy, so that the AlN/AE composite material can be widely applied to national defense, civil and automobile industries, and the effects of simultaneously lightening and resisting high temperature are achieved.
Drawings
In order to more clearly illustrate the embodiments of the present invention, the drawings that are used in the description of the embodiments or the prior art will be briefly described below.
FIG. 1 is a process flow chart of a preparation method of an AlN/VA44 composite material with excellent high-temperature-resistant mechanical properties provided in the embodiment 2 of the invention;
FIG. 2 is a metallographic structure diagram of as-cast VA44 alloy prepared in example 1 provided by the present invention;
FIG. 3 is a metallographic structure diagram of the as-cast AlN/VA44 composite material prepared in example 2 provided by the invention;
FIG. 4 is a metallographic structure diagram of an as-cast AlN/VA44 composite material prepared in example 3 provided by the present invention;
FIG. 5 is a graph showing the high temperature mechanical contrast of as-cast VA44 alloy/as-cast AlN/VA44 composite materials prepared in examples 1, 2 and 3 provided by the present invention;
fig. 6 is a high temperature mechanical comparison chart of the extruded VA44 alloy/extruded AlN/VA44 composite material prepared in examples 1, 2, and 3 provided by the present invention.
Detailed Description
The invention will now be described in further detail with reference to the accompanying drawings and examples which are given by way of illustration only and not by way of limitation, and are not intended to limit the scope of the invention.
When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as an upper range limit, or as a lower range limit, it is to be understood that any range is specifically disclosed by combining any pair of the upper range limit or preferred value with any lower range limit or preferred value, regardless of whether the range is specifically disclosed. Unless otherwise indicated, the numerical range values set forth herein are intended to include the endpoints of the range, and all integers and fractions within the range.
All percentages, parts, ratios, etc. herein are by weight unless otherwise specified.
The materials, methods, and examples herein are illustrative and, unless otherwise indicated, should not be construed as limiting.
In the following examples, pure magnesium ingots, pure aluminum ingots, magnesium gadolinium intermediate alloys and AlN particles are commercially available products, wherein the purity of the pure magnesium ingots is more than or equal to 99.95%, the purity of the pure zinc particles is more than or equal to 99.99%, and the average size of the AlN particles is 40nm;
gadolinium in the magnesium-gadolinium intermediate alloy accounts for 25-35% of the total mass of the magnesium base alloy;
the model of the adopted metallographic microscope is OLYMPUS PMG3;
the tensile mechanical properties tested were measured using the test standard of the high temperature tensile test method for metallic materials (ASTM E21-2009).
In the following examples, mg-4Gd-4Al (hereinafter referred to as VA 44) is taken as an example in the application, and the AlN/AE44 composite material with excellent high-temperature mechanical properties and the preparation method thereof provided by the application are described.
Example 1
The preparation method of the magnesium matrix alloy VA44 (Mg-4 Gd-4 Al) comprises the following steps:
1) Preparation of as-cast VA44 alloy
Calculating the mass of pure magnesium ingot, mg-30wt.% Gd and pure aluminum ingot required by smelting according to designed alloy components (the VA44 magnesium base alloy comprises Gd:4%, al:4% and the balance Mg) and the burning loss rate; grinding the alloy raw materials of the pure magnesium ingot, the magnesium gadolinium intermediate alloy (Mg-30 wt.% Gd) and the pure aluminum ingot, removing an oxide layer on the surface, proportioning according to the calculated mass and proportion, and preheating at 200 ℃;
after the high temperature resistance furnace is preheated for a period of time, pure magnesium is put into a crucible and clamped into the furnace, and high temperature of 740 ℃ is set, and 99 percent CO is introduced 2 +1％SF 6 A shielding gas; after the pure magnesium ingot is melted, skimming by a scum removing ladle, and clamping Mg-30wt.% Gd in a corresponding proportion into a crucible; after the alloy is completely melted, skimming the scum by a scum removing ladle, and adding pure aluminum ingots with corresponding proportions; taking out the matrix alloy from the high-temperature resistance furnace for casting after the alloy is completely melted, and cooling the matrix alloy to room temperature by water to obtain an as-cast VA44 alloy;
2) Solution treatment and hot extrusion of as-cast VA44 alloy
Wrapping a spindle of as-cast VA44 alloy with aluminum foil paper, placing the spindle in a crucible, and then completely covering the alloy with graphite to isolate air and prevent oxidation; then placing the crucible into a resistance furnace with the temperature of 520 ℃ for heat preservation for 8 hours, taking out a spindle, and cooling the spindle to room temperature by water to obtain a spindle of the solid solution state VA44 alloy;
placing a spindle of the solid solution state VA44 alloy into a resistance furnace at 385 ℃ for 2 hours of preheating, and directly performing hot extrusion under the conditions that the extrusion temperature is 385 ℃ and the extrusion ratio is 10 to obtain the extrusion state VA44 alloy;
3) 250 ℃ high temperature tensile test of as-cast and extruded VA44 alloy
And 3 high-temperature tensile samples are respectively cut from the as-cast VA44 alloy in the step 1) and the extruded VA44 alloy in the step 2), the total length of the tensile samples is 48mm, the gauge length is 18mm, the length of the end part is 12mm, the length of the middle section is 3mm, and the thickness of the tensile samples is 1.6mm. The tensile bars were incubated at 250℃for 15min, after which a high temperature tensile test at 250℃was directly performed, at a tensile rate of 1.5mm/min.
As can be seen from FIG. 2, the metallographic microstructure of the as-cast VA44 alloy prepared in the embodiment is shown in FIG. 2, and the second phase in the form of globular particles is hardly precipitated in the microstructure phase of the as-cast VA44 alloy; meanwhile, the tensile mechanical properties of the as-cast VA44 alloy and the extruded VA44 alloy at the high temperature of 250 ℃ are tested, and the results are shown in fig. 5 and 6, and as can be seen from fig. 5 and 6, the as-cast VA44 alloy in the implementation has the average yield strength, the tensile strength and the elongation rate of 33.9MPa, 96.8MPa and 38.5 percent respectively at the high temperature of 250 ℃; the average yield strength, the tensile strength and the elongation of the extruded VA44 alloy at the high temperature of 250 ℃ are 62.7MPa, 113.4MPa and 56.2 percent respectively; whether as-cast VA44 alloy or as-extruded VA44 alloy, the VA44 matrix alloy has very low tensile properties at high temperatures of 250 ℃.
Example 2
The preparation method of the AlN/VA44 composite material, as shown in figure 1, specifically comprises the following steps:
1) Preparation of AlN/VA44 alloy
Calculating the mass of pure magnesium ingots, mg-30wt.% Gd, pure aluminum ingots and AlN particles required by smelting according to designed alloy components (the VA44 magnesium base alloy comprises 4% of Gd, 4% of Al and the balance of Mg in percentage by mass) and the burning loss rate; grinding the alloy raw materials of the pure magnesium ingot, the magnesium gadolinium intermediate alloy (Mg-30 wt.% Gd) and the pure aluminum ingot, removing an oxide layer on the surface, proportioning according to the calculated mass and proportion, and preheating at 200 ℃;
preheating the high-temperature resistance furnaceAfter a period of time, the pure magnesium ingot is put into a crucible and clamped into a furnace, and high temperature of 740 ℃ is set, and 99 percent CO is introduced 2 +1％SF 6 A shielding gas; after the pure magnesium ingot is melted, skimming by a scum removing ladle, and clamping Mg-30wt.% Gd in a corresponding proportion into a crucible; after the alloy is completely melted, the scum is fished out by a scum-beating spoon, and then pure aluminum ingots with corresponding proportions are added. After the alloy was completely melted, the temperature of the resistance furnace was set to 635 ℃, 0.3% (mass percent) AlN particles wrapped with a packaging bag were added in the semi-solid state of the alloy, and mechanical stirring was performed for 5min at a stirring speed of 300rpm until the melt was in a conical vortex shape.
Heating to 680 ℃, extending an ultrasonic probe into the surface of the molten alloy, and carrying out ultrasonic stirring for 10min, wherein the ultrasonic frequency is 19.9kHz. After the ultrasonic stirring is finished, cooling to 650 ℃, and carrying out heat preservation and standing for 5 min; finally, water-cooling to room temperature to obtain the as-cast AlN/VA44 composite material.
2) Solution treatment and hot extrusion of as-cast AlN/VA44 composite material
Carrying out solution treatment for 520 ℃ for 8 hours on the spindle of the as-cast AlN/VA44 composite material obtained in the step 1): wrapping a spindle of the cast AlN/VA44 composite material with aluminum foil paper, placing the spindle in a crucible, and then completely covering the alloy with graphite to isolate air and prevent oxidation; and then placing the crucible into a resistance furnace with the temperature of 520 ℃ for heat preservation for 8 hours, taking out the spindle, and cooling the spindle to room temperature by water to obtain the spindle of the AlN/VA44 composite material in a solid solution state.
Placing a spindle of the solid solution AlN/VA44 composite material into a resistance furnace at 385 ℃ for 2 hours to preheat, and then directly performing hot extrusion under the conditions that the extrusion temperature is 385 ℃ and the extrusion ratio is 10 to obtain the extrusion state AlN/VA44 composite material;
3) 250 ℃ high temperature tensile test of as-cast and extruded AlN/VA44 composite materials
And 3 high-temperature tensile samples are respectively cut from the as-cast AlN/VA44 composite material in the step 1) and the extruded AlN/VA44 composite material in the step 2), the total length of the tensile samples is 48mm, the gauge length is 18mm, the end length is 12mm, the middle section length is 3mm, and the thickness of the tensile samples is 1.6mm. The tensile bars were incubated at 250℃for 15min, after which a high temperature tensile test at 250℃was directly performed, at a tensile rate of 1.5mm/min.
As shown in FIG. 3, the metallographic microstructure of the as-cast AlN/VA44 composite material prepared in the embodiment is shown in FIG. 3, and the addition of AlN particles leads to a significant increase of the spherulitic second phase in the alloy and is dispersed uniformly in grains. This demonstrates that the addition of AlN particles has a significant regulatory effect on the second phase structure of the VA44 matrix alloy and can promote the second phase distribution state to exhibit good intra-crystalline dispersion uniform distribution. This may be due to: the addition of AlN initiates the interfacial reaction of part of AlN and RE element, thereby promoting the generation of spherulitic Al-RE phase in the crystal; in addition, because RE element is uniformly distributed in the crystal, the ultrasonic stirring promotes the uniform distribution of AlN in the crystal, so that the Al-RE phase generated by the interface reaction is uniformly dispersed in the crystal.
Meanwhile, the tensile mechanical properties of the as-cast AlN/VA44 composite material and the extruded AlN/VA44 composite material at the high temperature of 250 ℃ are tested, and the results are shown in fig. 5 and 6, wherein the average yield strength, the tensile strength and the elongation of the as-cast AlN/VA44 composite material are respectively 44.4MPa, 102.5MPa and 31.5%, and compared with the as-cast VA44 alloy, the yield strength is improved by about 10MPa, and the improvement range is about 31%; the tensile strength is improved by about 6MPa, and the lifting amplitude is about 6%. This shows that the improvement of the second phase structure brought by the addition of AlN particles can obviously and effectively improve the high-temperature performance of the VA44 alloy; the average yield strength, the tensile strength and the elongation of the extruded AlN/VA44 composite material are 72.3MPa, 120.5MPa and 46.4 percent respectively, and compared with the extruded matrix alloy, the yield strength is improved by about 10MPa, and the improvement amplitude is about 15 percent; the tensile strength is improved by about 7MPa, and the lifting amplitude is about 6%.
Example 3
The preparation method of the AlN/VA44 composite material comprises the following steps:
1) Preparation of AlN/VA44 alloy
Calculating the mass of pure magnesium ingots, mg-30wt.% Gd, pure aluminum ingots and AlN particles required by smelting according to designed alloy components (the VA44 magnesium base alloy comprises 4% of Gd, 4% of Al and the balance of Mg in percentage by mass) and the burning loss rate; grinding the alloy raw materials of the pure magnesium ingot, the magnesium gadolinium intermediate alloy (Mg-30 wt.% Gd) and the pure aluminum ingot, removing an oxide layer on the surface, proportioning according to the calculated mass and proportion, and preheating at 200 ℃;
after the high temperature resistance furnace is preheated for a period of time, the pure magnesium ingot is put into a crucible and clamped into the furnace, and high temperature of 740 ℃ is set, and 99 percent CO is introduced 2 +1％SF 6 A shielding gas; after the pure magnesium ingot is melted, skimming by a scum removing ladle, and clamping Mg-30wt.% Gd in a corresponding proportion into a crucible; after the alloy is completely melted, the scum is fished out by a scum-beating spoon, and then pure aluminum ingots with corresponding proportions are added. After the alloy was completely melted, the temperature of the resistance furnace was set to 635 ℃, 0.7% (mass percent) AlN particles wrapped with a packaging bag were added in the semi-solid state of the alloy, and mechanical stirring was performed for 5min at a stirring speed of 300rpm until the melt was in a conical vortex shape.
Heating to 680 ℃, extending an ultrasonic probe into the surface of the molten alloy, and carrying out ultrasonic stirring for 10min, wherein the ultrasonic frequency is 19.9kHz. After the ultrasonic stirring is finished, cooling to 650 ℃, and carrying out heat preservation and standing for 5 min; finally, water-cooling to room temperature to obtain the as-cast AlN/VA44 composite material.
2) Solution treatment and hot extrusion of as-cast AlN/VA44 composite material
Carrying out solution treatment for 520 ℃ for 8 hours on the spindle of the as-cast AlN/VA44 composite material obtained in the step 1): wrapping a spindle of the cast AlN/VA44 composite material with aluminum foil paper, placing the spindle in a crucible, and then completely covering the alloy with graphite to isolate air and prevent oxidation; and then placing the crucible into a resistance furnace with the temperature of 520 ℃ for heat preservation for 8 hours, taking out the spindle, and cooling the spindle to room temperature by water to obtain the spindle of the AlN/VA44 composite material in a solid solution state.
Placing a spindle of the solid solution AlN/VA44 composite material into a resistance furnace at 385 ℃ for 2 hours to preheat, and then directly performing hot extrusion under the conditions that the extrusion temperature is 385 ℃ and the extrusion ratio is 10 to obtain the extrusion state AlN/VA44 composite material;
3) 250 ℃ high temperature tensile test of as-cast and extruded AlN/VA44 composite materials
And 3 high-temperature tensile samples are respectively cut from the as-cast AlN/VA44 composite material in the step 1) and the extruded AlN/VA44 composite material in the step 2), the total length of the tensile samples is 48mm, the gauge length is 18mm, the end length is 12mm, the middle section length is 3mm, and the thickness of the tensile samples is 1.6mm. The tensile bars were incubated at 250℃for 15min, after which a high temperature tensile test at 250℃was directly performed, at a tensile rate of 1.5mm/min.
As shown in FIG. 4, as the addition amount of AlN particles increases from 0.3% to 0.7%, the second phase in the form of pellets in the composite increases further, and the dispersion of the second phase in the crystal grains is maintained to be uniform, and the microstructure of the VA44 matrix alloy is further improved by the increase of the AlN particle content. Meanwhile, the tensile mechanical properties of the as-cast AlN/VA44 composite material and the extruded AlN/VA44 composite material at the high temperature of 250 ℃ are tested, and the results are shown in the figures as shown in the figures 5 and 6, wherein the average yield strength, the tensile strength and the elongation of the as-cast AlN/VA44 composite material are respectively 64.2MPa, 109.2MPa and 27.1 percent, and compared with the as-cast VA44 alloy, the yield strength is improved by about 30MPa, and the improvement amplitude is about 89 percent; the tensile strength is improved by about 12MPa, and the lifting amplitude is about 13%; this shows that as the AlN particle content increases, the more the spherulitic second phase in the crystal promotes to be generated, the more the high-temperature performance of the as-cast AlN/VA44 composite material is improved; the average yield strength, the tensile strength and the elongation of the extruded AlN/VA44 composite material are respectively 81.4MPa, 125.8MPa and 34.1 percent, and compared with the extruded matrix alloy, the yield strength is improved by about 20MPa, and the improvement amplitude is about 30 percent; the tensile strength is improved by about 13MPa, and the lifting amplitude is about 11%.
The AlN/AE44 composite material with excellent high-temperature mechanical property provided by the invention can be seen through comprehensive comparison of the microstructures and the high-temperature properties of the examples 1, 2 and 3: the addition of AlN particles can promote the precipitation of most of the spherulitic second phase in the VA44 alloy, the spherulitic second phase can effectively prevent dislocation movement in the crystal during the alloy deformation process, and the dispersion is kept uniformly distributed in the crystal grains, so that the high-temperature performance of the alloy is obviously strengthened. When the addition amount of AlN particles in the alloy is 0.3-0.7 wt.%, the performance of the composite material can be improved to a large extent at a high temperature of 250 ℃. Especially when the addition amount of AlN particles is 0.7wt.%, the yield strength of the as-cast AlN/VA44 composite material is improved by about 30MPa and the improvement range is about 89% relative to the VA44 matrix alloy; the tensile strength is improved by about 12MPa, and the lifting amplitude is about 13%. The yield strength of the extruded AlN/VA44 composite material is improved by about 20MPa, and the improvement amplitude is about 30%; the tensile strength is also improved by about 12MPa, and the improvement range is about 11%. Comprehensive comparison shows that by introducing low-content AlN particles, effective regulation and control of a second phase structure in the AE44 alloy can be realized through interface reaction, so that the second phase in the alloy crystal is obviously increased, a well-dispersed state is maintained, dislocation movement in the alloy deformation process is obviously blocked, and the high-temperature performance of the alloy is greatly improved.
According to the invention, alN/VA44 magnesium alloy composite material is prepared by introducing AlN particles (40 nm) with low addition amount into the matrix alloy through a method of mechanical stirring and ultrasonic stirring, so that the formation and dispersion conditions of a second phase structure of the Mg-4Gd-4Al alloy are effectively improved, and the high-temperature yield strength and the tensile strength at 250 ℃ are effectively improved.
The above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention, and are intended to be included within the scope of the appended claims and description.
Claims (7)
1. The preparation method of the AlN/AE44 composite material with excellent high-temperature mechanical properties is characterized by comprising the following steps:
1) Smelting and ingot casting of the composite material: according to the formula requirement, adding AlN particles into a magnesium matrix alloy melt, and carrying out preliminary dispersion on the AlN particles by adopting mechanical stirring to obtain a composite melt; after the composite melt is heated to the liquidus temperature, further dispersing the composite melt by adopting ultrasonic waves, and after the dispersion is completed, carrying out heat preservation and standing, and then casting and forming to obtain an ingot;
2) Carrying out homogenization heat treatment and extrusion molding on the cast ingot obtained in the step 1) to obtain an AlN/AE44 composite material with excellent high-temperature mechanical properties;
wherein the temperature of the AlN/AE44 during the homogenization heat treatment is 520 ℃ and the time is 8 hours; the extrusion molding conditions are as follows: the extrusion temperature is 385 ℃, and the extrusion ratio is 10;
and the composite material comprises the following components in percentage by mass: magnesium base alloy: 99-99.8%, alN particles: 0.2% -1.0%; wherein the magnesium base alloy comprises RE:3.5-4.5%, al 3.5-4.5% and Mg in balance.
2. The method for preparing an AlN/AE44 composite material having excellent high-temperature mechanical properties according to claim 1, wherein the AlN particles have a particle size of 40-60nm.
3. The method for preparing an AlN/AE44 composite material with excellent high-temperature mechanical properties according to claim 1, wherein the preparation process of the magnesium base alloy melt is:
the volume ratio is 99: CO of 1 2 And SF (sulfur hexafluoride) 6 Under the protection of mixed gas, placing the pure magnesium ingot with the mass percentage into a resistance furnace, heating up to 730-750 ℃ along with the resistance furnace, and stirring uniformly after the pure magnesium ingot is completely melted to obtain a magnesium melt; then adding magnesium gadolinium intermediate alloy and pure aluminum ingot into magnesium melt, standing for 5-10min until the magnesium melt is completely melted, uniformly stirring, and scraping scum on the surface of the alloy melt to obtain the magnesium base alloy melt.
4. The method for preparing an AlN/AE44 composite material having excellent high temperature mechanical properties according to claim 3 wherein when said AlN particles are added, the temperature of the magnesium base alloy melt is lowered to 620-640℃and the mechanical stirring speed is 100-500rpm and the stirring time is 5-10min.
5. The method for preparing an AlN/AE44 composite material having excellent high temperature mechanical properties according to claim 4 wherein said AlN particles are added to a magnesium base alloy melt and mechanically stirred uniformly to obtain a composite melt, the composite melt is heated to 680-690 ℃ and dispersed by ultrasonic waves with a frequency of 19.5-20.7kHz for 8-12min.
6. The method for preparing an AlN/AE44 composite material having excellent high-temperature mechanical properties according to claim 5 wherein the composite melt is subjected to ultrasonic dispersion to remove dross on the surface of the composite melt, the temperature of the composite melt is lowered to 640-650 ℃, and the composite melt is allowed to stand for 5-10min and then cast into a metal mold for cooling and solidification.
7. The method for preparing an AlN/AE44 composite material having excellent high-temperature mechanical properties according to claim 3, further comprising the step of preheating the pure magnesium ingot, magnesium gadolinium intermediate alloy and pure aluminum ingot during the preparation of the magnesium base alloy melt.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08104931A (en) * | 1994-10-05 | 1996-04-23 | Agency Of Ind Science & Technol | Method for imparting superplasticity to ceramic particle reinforced magnesium-base composite material by molten metal stirring method |
| WO2005111251A1 (en) * | 2004-05-19 | 2005-11-24 | Institute Of Metal Research Chinese Academy Of Sciences | A high-strength, high-toughness cast magnesium alloy and the method thereof |
| CN101148722A (en) * | 2007-11-08 | 2008-03-26 | 上海交通大学 | In situ self-generation aluminum nitride and magnesium disilicide enhanced magnesium-base composite material and preparation method thereof |
| CN102051509A (en) * | 2010-12-28 | 2011-05-11 | 西安工业大学 | High-toughness heat-resistant Mg-Al-RE-Mn wrought magnesium alloy and preparation method of plate made of same |
| CN114277277A (en) * | 2021-12-22 | 2022-04-05 | 重庆大学 | AlN/Al particle reinforced magnesium-aluminum rare earth based composite material and preparation method thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6594663B2 (en) * | 2015-05-27 | 2019-10-23 | 本田技研工業株式会社 | Heat-resistant magnesium casting alloy and its manufacturing method |
| US10370744B2 (en) * | 2016-06-14 | 2019-08-06 | King Fahd University Of Petroleum And Minerals | Reinforced magnesium composite and a method of producing thereof |
-
2022
- 2022-12-30 CN CN202211722809.6A patent/CN115976384B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08104931A (en) * | 1994-10-05 | 1996-04-23 | Agency Of Ind Science & Technol | Method for imparting superplasticity to ceramic particle reinforced magnesium-base composite material by molten metal stirring method |
| WO2005111251A1 (en) * | 2004-05-19 | 2005-11-24 | Institute Of Metal Research Chinese Academy Of Sciences | A high-strength, high-toughness cast magnesium alloy and the method thereof |
| CN101148722A (en) * | 2007-11-08 | 2008-03-26 | 上海交通大学 | In situ self-generation aluminum nitride and magnesium disilicide enhanced magnesium-base composite material and preparation method thereof |
| CN102051509A (en) * | 2010-12-28 | 2011-05-11 | 西安工业大学 | High-toughness heat-resistant Mg-Al-RE-Mn wrought magnesium alloy and preparation method of plate made of same |
| CN114277277A (en) * | 2021-12-22 | 2022-04-05 | 重庆大学 | AlN/Al particle reinforced magnesium-aluminum rare earth based composite material and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 镁合金塑性加工技术发展及应用;潘复生等;金属学报;第57卷(第11期);第1362-1379页 * |
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