CN104745901A - Indirect extrusion casting method of wrought aluminum alloy castings - Google Patents

Abstract

The invention discloses an indirect extrusion casting method of wrought aluminum alloy castings. The method comprises the steps of alloy preparation, alloy smelting, indirect extrusion casting and heat treatment, wherein all components are prepared by mass percentage; Si, Cu and Cr in alloys are respectively added by intermediate alloys of an aluminum silicon alloy, an aluminum copper alloy and an aluminum chrome alloy; Mg and Al are respectively added by pure magnesium and pure aluminum; firstly, the pure aluminum and the intermediate alloys of aluminum silicon, aluminum copper and aluminum chrome are added; a refining agent is added for refining; then, magnesium is added after the temperature reduction; and finally, the temperature is adjusted and then the indirect extrusion casting is performed. The method has the prominent advantages of no need of quantitative casting, easy control of casting size, realization of near-net forming, reduction of subsequent processing, realization of high material utilization rate above 90%, reduction of cost, and capabilities of producing castings with more complex shapes and larger wall thickness differences and enabling the castings to have high mechanical performance.

Description

The method for indirect extrusion casting of wrought aluminium alloy foundry goods

 

Technical field

The invention belongs to casting technology field, be specifically related to a kind of method for indirect extrusion casting of wrought aluminium alloy foundry goods.

 

Background technology

Aluminum alloy casting Foundry Production also also exists some problem at present, as cast-internal is organized thick, often has the casting flaw such as shrinkage porosite, pore, causes mechanical castings to be not so good as forging high.Casting process is many, and some technological processs are also difficult to accurate control, and make casting quality stable not, scrap rate is high, contaminate environment, and energy consumption is high.

 

Summary of the invention

In order to overcome the above-mentioned technical problem that prior art field exists, the object of the invention is to, a kind of method for indirect extrusion casting of wrought aluminium alloy foundry goods is provided, present method does not need quantitative pouring, easy control casting dimension, near-net-shape, reduces following process, material use efficiency, up to more than 90%, reduces costs.

The method for indirect extrusion casting of wrought aluminium alloy foundry goods provided by the invention, comprises the following steps:

(1) alloy preparation: each elementary composition of alloy is by mass percentage: Si:0.4 ~ 1.2%; Cu:0.2 ~ 0.9%; Mg:0.8 ~ 1.4%; Cr:0.02 ~ 0.4%; Al: surplus; In alloy preparation, Si, Cu, Cr add by master alloy aluminum silicon alloy, aluminum-copper alloy, aluminum chromium respectively, Mg and Al adds by pure magnesium, fine aluminium respectively;

(2) alloy melting: by the alloy of above-mentioned preparation, first fine aluminium and aluminium silicon, aluminum bronze, aluminium chromium hardener are added smelting furnace intensification fusing, heat up 700 ~ 740 DEG C, add refining agent refining, add magnesium after being cooled to 680 ~ 700 DEG C, adjustment temperature to 720 ~ 740 DEG C start indirect extrusion casting;

(3) indirect extrusion casting: aluminium liquid is poured in die cavity, matched moulds, pressurization, the processing parameter of indirect extrusion casting: moulding pressure is 50 ~ 200MPa, the dwell time is 15 ~ 35s, and teeming temperature is 690 ~ 730 DEG C, and die temperature is 60 ~ 160 DEG C;

(4) thermal treatment: 1. solution treatment: solid solubility temperature 515 ± 5 DEG C, solution time 6 ~ 10h, foundry goods to be come out of the stove to water 1 ~ 15s transfer time, type of cooling room temperature water-cooled; 2. an ageing treatment is carried out immediately after solution treatment: aging temp (150 ~ 165) ± 5 DEG C, aging time 6 ~ 14h, type of cooling air cooling; 3. secondary ageing process: aging temp (165 ~ 175) ± 5 DEG C, aging time 1 ~ 3h, type of cooling air cooling.

The method for indirect extrusion casting of wrought aluminium alloy foundry goods provided by the invention, its beneficial effect is, does not need quantitative pouring, easily controls casting dimension; Near-net-shape, reduce following process, material use efficiency, up to more than 90%, reduces costs; Can production shape more complicated, the larger foundry goods of wall thickness difference; Mechanical property is high.

 

Embodiment

Below in conjunction with an embodiment, the method for indirect extrusion casting of wrought aluminium alloy foundry goods provided by the invention is described in detail.

Embodiment

(1) alloy preparation: each elementary composition of alloy is by mass percentage: Si:1.2%; Cu:0.5%; Mg:1.2%; Cr:0.3%; Al: surplus; In alloy preparation, Si, Cu, Cr add by master alloy aluminum silicon alloy, aluminum-copper alloy, aluminum chromium respectively, Mg and Al adds by pure magnesium, fine aluminium respectively;

(2) alloy melting: by the alloy of above-mentioned preparation, first fine aluminium and aluminium silicon, aluminum bronze, aluminium chromium hardener are added smelting furnace intensification fusing, heat up 740 DEG C, add refining agent refining, add magnesium after being cooled to 700 DEG C, adjustment temperature to 720 starts indirect extrusion casting;

(3) indirect extrusion casting: aluminium liquid is poured in die cavity, matched moulds, pressurization, the processing parameter of indirect extrusion casting: moulding pressure is 50MPa, the dwell time is 35s, and teeming temperature is 690 DEG C, and die temperature is 160 DEG C;

(4) thermal treatment: 1. solution treatment: solid solubility temperature 520 DEG C, solution time 8h, foundry goods to be come out of the stove to water 15s transfer time, type of cooling room temperature water-cooled; 2. an ageing treatment is carried out immediately after solution treatment: aging temp 165 DEG C, aging time 8h, type of cooling air cooling; 3. secondary ageing process: aging temp 175 DEG C, aging time 2.3h, type of cooling air cooling.

The method for indirect extrusion casting of wrought aluminium alloy foundry goods, base material and strongthener are combined good in recombination process median surface, higher toughness, intensity and wear resistance can be reached with the component of the method manufacture, be not only applicable to carry out compound using ferrous metal as base material, be applicable to carry out compound using non-ferrous metal as base material yet.

Claims (1)

1. a molding sand method for casting production for the indirect extrusion foundry goods of aluminum alloy casting, is characterized in that: said method comprising the steps of:

(1) alloy preparation: each elementary composition of alloy is by mass percentage: Si:0.4 ~ 1.2%; Cu:0.2 ~ 0.9%; Mg:0.8 ~ 1.4%; Cr:0.02 ~ 0.4%; Al: surplus; In alloy preparation, Si, Cu, Cr add by master alloy aluminum silicon alloy, aluminum-copper alloy, aluminum chromium respectively, Mg and Al adds by pure magnesium, fine aluminium respectively;

(2) alloy melting: by the alloy of above-mentioned preparation, first fine aluminium and aluminium silicon, aluminum bronze, aluminium chromium hardener are added smelting furnace intensification fusing, heat up 700 ~ 740 DEG C, add refining agent refining, add magnesium after being cooled to 680 ~ 700 DEG C, adjustment temperature to 720 ~ 740 DEG C start indirect extrusion casting;

(3) indirect extrusion casting: aluminium liquid is poured in die cavity, matched moulds, pressurization, the processing parameter of indirect extrusion casting: moulding pressure is 50 ~ 200MPa, the dwell time is 15 ~ 35s, and teeming temperature is 690 ~ 730 DEG C, and die temperature is 60 ~ 160 DEG C;

(4) thermal treatment: 1. solution treatment: solid solubility temperature 515 ± 5 DEG C, solution time 6 ~ 10h, foundry goods to be come out of the stove to water 1 ~ 15s transfer time, type of cooling room temperature water-cooled; 2. an ageing treatment is carried out immediately after solution treatment: aging temp (150 ~ 165) ± 5 DEG C, aging time 6 ~ 14h, type of cooling air cooling; 3. secondary ageing process: aging temp (165 ~ 175) ± 5 DEG C, aging time 1 ~ 3h, type of cooling air cooling.