CN1041900C

CN1041900C - Vacuum extrusion and special heat treatment technology for producing high-strength shockproof aluminium casting

Info

Publication number: CN1041900C
Application number: CN94113112A
Authority: CN
Inventors: 邱表来
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-10-20
Filing date: 1994-10-20
Publication date: 1999-02-03
Anticipated expiration: 2014-10-20
Also published as: CN1120986A

Abstract

The present invention relates to a novel technique for vacuum extrusion and the treatment of special heat, which is used for producing a shockproof aluminum casting with high strength. A push rod box of a mould and an injection cylinder are connected with a vacuum system, and a casting machine is connected with the mould. The vacuum extrusion moulding process uses the technique including two high-pressure steps, two low-pressure steps and two refining steps that the aluminum alloy liquid is refined for two times, is moulded in a filling mode at low temperature and low speed, the high pressure is maintained in a time delay mode; thereby, a demoulded aluminum casting is treated in a specific heating mode when the time effect of the aluminum casting is strengthened in the specific environment. The present invention has the advantages of simple technique, advanced and mature technology, obvious reduction of material consumption, high productive efficiency, low product cost, etc. In addition, the aluminum casting has the advantages of beautiful appearance, high intensity and good shock resistance. The qualified rate of the aluminum casting is over 96%.

Description

A kind of vacuum press and heat-treating methods of producing the high-strength anti-shock aluminum casting

The invention belongs to a kind of vacuum press and heat-treating methods of producing aluminum casting, be meant a kind of vacuum press and heat-treating methods of producing the high-strength anti-shock aluminum casting especially.

Adopt the process production intensity height of traditional steel die cast, low pressure casting, the aluminium alloy castings that anti-seismic performance is good, distinct issues are that raw materials consumption is big, and product percent of pass is low, and mechanical performance is difficult to reach instructions for use.With the aluminium alloy castings that pressure casting process is produced, because the difficult problem of " quench and bubble " does not all have to solve both at home and abroad, product can not satisfy the serviceability of high-strength anti-shock equally.Produce the high-strength anti-shock aluminium alloy castings with pressure, extruding casting technology, though mechanical performance can satisfy instructions for use, the product percent of pass height, but owing to used a kind of " quenching strengthening heat treatment " technology, foundry goods is in heat treatment process, and the processing time is long, power consumption is many, production efficiency is low, has improved production cost greatly, and is very uneconomical economically.So, no matter be to use the user of high-strength anti-shock aluminum casting both at home and abroad, still produce the specialized factory of high-strength anti-shock aluminum casting, all centering on reduction castings production cost, enhance product performance and the problem of economic benefit is thought hard, think idea, seek a kind of new process of the production high-strength anti-shock aluminum casting that can reduce production costs and can raise the efficiency.

The objective of the invention is at the problems referred to above, what provide a kind ofly can reduce raw materials consumption greatly, simplify the quenching strengthening treatment process, reduce energy loss, reduce production costs, enhance productivity and a kind of vacuum press and heat-treating methods of producing the high-strength anti-shock aluminum casting of the serviceability of product.

The technical scheme that the present invention finishes is on the basis of existing steel die cast, low pressure casting and pressure extrusion casting, implements the new process for producing that a kind of vacuum press combines with extraordinary heat treatment phase.Still adopt running gate system in punching block, the low-pressure casting process and the row in the pressure casting process system of overflowing at the mould design aspect, note increasing the thickness and the width of ingate, the ingate thickness that makes it in the running gate system is the 30-50% of foundry goods thickest, and width is the 60-80% of casting length.Ejector pin of die set case and shot sleeve connect by vacuum system, so that set up the vacuum that overbottom pressure is the 20-100 millimetres of mercury.Die casting machine connects mould, carries out extrusion under vacuum.At the aluminium alloy trade mark is on the basis of ZL111, ZL112, and the content of the magnesium in the alloy composition, copper, manganese, iron is done rationally to adjust, and adopts " two Senior Two are hanged down two refinings " technology; " two refinings " is the temperature of aluminum alloy melt when being elevated to 710-750 ℃, successively carries out double refining, removes gas, residue in the alloy liquid; " two is low " is the aluminum alloy melt cooling through refining, is that 600-650 ℃ low temperature low speed fills type during with the realization vacuum press, and promptly " the low temperature of watering " and pressure injection speed are per second 4-20 centimetre " low pressure speed "; " two height " is " high pressure ratio " and " high time-delay ", and promptly the pressure ratio during vacuum press is greater than 700 kilograms every square centimeter, pressurize under high pressure conditions, time expand 8-40 kind second.The pressurize time-delay finishes, the aluminum casting that die sinking is taken out, by in the case that successively is deposited in additional heat may not from bottom to up, utilized in this particular environment that the heat of aluminum casting own heat-treats " reinforcement timeliness " 2-5 hour, promptly finish the extraordinary heat treatment of high-strength anti-shock aluminium alloy castings.Facts have proved, the foundry goods that obtains like this, surface-brightening, fractograph densification, casting flaws such as pore, shrinkage porosite, shrinkage cavity, slag inclusion are few, through suppressing the test ne-leakage, the section of foundry goods body sampling is tested, and tensile strength is 275-342mpa, Brinell hardness HB is 92-118, percentage elongation is 2.8-5.6%, and mechanical property surpasses designing requirement, and product percent of pass is more than 96%.

Advantage of the present invention is; Combine the strong point of steel die cast, low pressure casting, compression casting and process for suction casting, utilized the heat treatment rule advantage of diving and pressing in material composition and the extrusion process process cleverly; The cast(ing) surface light of producing, the fractograph densification, casting flaw is few, the qualification rate height; Chemical analysis is stable; Greatly reduce raw materials consumption, reduce by 45%, reduce by 25% than low pressure casting than steel die cast; This extraordinary heat treated equipment is simple, has reduced the equipment investment of conventional well formula heat-treatment furnace and the power consumption in the heat treatment process, has shortened heat treatment time, enhances productivity more than 5 times; Production cost reduces more than 50%; Manufacturing technique method is simply unique, and the advanced technology maturation is easy to utilize; This heat treatment method, also beyond example has abroad at present improved the mechanical performance of high-strength anti-shock aluminium alloy castings conscientiously, can prolong the service life of product greatly, can produce good economic benefits and social benefit.

Most preferred embodiment of the present invention is: with the damping sleeve pipe on southern 125 motorcycles is example, this high-strength anti-shock aluminium alloy castings, and the mechanical property of designing requirement is respectively: tensile strength is 250mpa, and Brinell hardness HB is 85-105, and percentage elongation is 2%.Adopt this production technology test one: when aluminum alloy melt is elevated to 730 ℃, refining just obtains pure aluminum alloy melt twice, when being cooled to 610 ℃, pressure with 780 kilograms every square centimeter, the pressure injection speed that per second is 4 centimetres is carried out extrusion under vacuum, die sinking after 30 seconds of pressurize, foundry goods was strengthened timeliness 2 hours in the specific environment of not heating separately.Sampling detects through section, and tensile strength is 320mpa, and Brinell hardness HB is 110, and percentage elongation is 5.5%, and chemical analysis is stable.Adopt this production technology test two: when aluminum alloy melt is warming up to 750 ℃, successively carry out twice refining, remove the gas residue in the aluminum alloy melt, when being cooled to 640 ℃, with 860 kilograms every square centimeter pressure, the pressure speed that per second is 20 centimetres is carried out extrusion under vacuum.Die sinking after 10 seconds of pressurize, foundry goods was strengthened timeliness 4.5 hours in the specific environment of not heating separately.Sampling detects through section, and tensile strength is 285mpa, and Brinell hardness HB is 98, and percentage elongation is 3.1%.All above the product design requirement.

Extruding of this vacuum and extraordinary heat treatment technics not only adapt to the high-strength anti-shock aluminium alloy sleeve pipe of producing on southern 125 motorcycles, and adapt to the production of the high-strength anti-shock aluminium alloy castings that uses on all motorcycles, the automobile, all can obtain satisfied effect.

Claims

1, a kind of vacuum press and heat-treating methods of producing the high-strength anti-shock aluminum casting, the overflow design of system of the row who comprises the running gate system of punching block, low pressure casting of mould structure and employing thereof and compression casting, evacuated die-casting process equipment is characterized in that vacuum press and heat-treating methods are; The ejector pin of die set case is connected vacuum system with shot sleeve, sets up the vacuum that overbottom pressure is the 20-100 millimetres of mercury, and die casting machine connects mould, and the aluminum alloy melt that carries out the extrusion under vacuum employing carries out refining exhaust deslagging in the time of 710-750 ℃; When the aluminum alloy melt after the refining drops to 600-650 ℃, the pressure ratio of vacuum press greater than 700 kilograms every square centimeter high pressure conditions under, pressure injection speed with per second 4-20 centimetre is filled type, pressurize under greater than 700 kilograms every square centimeter high pressure conditions, prolong dwell time 8-40 second, strengthen timeliness 2-5 hour after the foundry goods depanning, finish heat treatment.

2, vacuum press according to claim 1 and heat-treating methods is characterized in that aluminum alloy melt in the time of 710-750 ℃, carries out double refining, the exhaust deslagging.

3, vacuum press according to claim 1 and heat-treating methods, it is characterized in that the aluminum casting depanning after, the heat of utilization itself is strengthened timeliness in case.