CN101831577A

CN101831577A - Aluminum magnesium alloy

Info

Publication number: CN101831577A
Application number: CN 201010172444
Authority: CN
Inventors: 陈新华
Original assignee: CHANGZHOU HUACHEN FOUNDRY Co Ltd
Current assignee: CHANGZHOU HUACHEN FOUNDRY Co Ltd
Priority date: 2010-05-14
Filing date: 2010-05-14
Publication date: 2010-09-15

Abstract

The invention discloses an aluminum magnesium alloy for casting castings with elongation of over 10 percent. The aluminum magnesium alloy comprises the following components in percentage by weight: 3.8 to 4.5 percent of Mg, 0.3 to 0.4 percent of Cu, 0.2 to 0.23 percent of Ti, less than or equal to 0.1 percent of Fe, less than or equal to 0.1 percent of Si and the balance of Al. All properties of the castings meet the requirement by effectively controlling the components of the aluminum magnesium alloy, wherein the control of the adding amount of the Ti is favorable for improving the plasticity and tenacity of the alloy, the reasonable adjustment of the component content of Cu and Mg can ensure that the elongation of the castings is over 10 percent so as to play a good role in solid dissolving strengthening on the alloy, and the strict control of Fe and Si elements belonging to impurities meets the requirement of casting and producing high-end mechanical parts.

Description

A kind of aluminum magnesium alloy

Technical field

The present invention relates to casting technology field, especially a kind of aluminum magnesium alloy that is used for casting.

Background technology

General principal element is an aluminium in the aluminum magnesium alloy, mix a spot of magnesium again or other metallic substance is strengthened its hardness, improve its mechanical property, satisfy different user demands, therefore aluminum magnesium alloy is light with the hard amount of its matter, density is low, thermal diffusivity is better, crushing resistance is widely used in electronics by force, machinery, fields such as building, wherein use often starting material as foundry machinery part foundry goods at mechanical field, and as foundry goods, not only to have certain tensile strength, lower yield strength and hardness, especially should have unit elongation preferably, usually require unit elongation more than 10% in some high-end fields, but at present by the foundry goods of aluminum magnesium alloy as raw material institute Foundry Production, though a lot of measures have been taked in the casting technique aspect, at chemical index, mechanical property, aspects such as surface quality casting dimension all can meet the requirements, but unit elongation is difficult to reach more than 10% all the time.

Summary of the invention

The technical problem to be solved in the present invention is: overcome the deficiency of prior art, a kind of aluminum magnesium alloy is provided, solve existing aluminum magnesium alloy when carrying out Foundry Production as raw material, the foundry goods unit elongation of gained is difficult to reach the problem more than 10%.

The technical solution adopted for the present invention to solve the technical problems is: a kind of aluminum magnesium alloy, the weight percent of its each component is: Mg:3.8%～4.5%, Cu:0.3%～0.4%, Ti:0.2%～0.25%, Fe: Si≤0.1% :≤0.1%, and surplus is Al.

The invention has the beneficial effects as follows: the present invention is by the effective control to each component of aluminum magnesium alloy, make the every performance of foundry goods of being cast all meet the requirements, the addition of Ti wherein controlled well helps to improve the plasticity toughness of alloy, rationally adjust the component content of Cu and Mg, can guarantee that the foundry goods unit elongation is more than 10%, alloy is played solution strengthening effect preferably, Fe and Si are belonged to the then strict control of element of impurity, in the hope of reaching the requirement of the high-end mechanical component of Foundry Production.

Embodiment

The present invention is further illustrated in conjunction with the preferred embodiments now.

Embodiment 1: a kind of aluminum magnesium alloy, be used to cast bullet train motor front end end cover, the weight percent of its each component is: Mg:4.2%, Cu:0.32%, Ti:0.22%, Fe:0.085%, Si:0.09%, surplus is Al, will carry out casting processing after its fusing, and the gained foundry goods is heat-treated on request, promptly obtain the motor front end end cover foundry goods of moulding, sample presentation detects through state-run 307 factory physical and chemical testing centers, and detected result is as follows: tensile strength Rm:205Mp, lower yield strength R _P0.2: 113Mp, hardness HB:63.3, unit elongation A:10.5%, institute's measured motor front end end cover cast properties all meets the requirements, and especially unit elongation has satisfied the requirement that reaches more than 10%, judges that foundry goods is qualified.

Embodiment 2: a kind of aluminum magnesium alloy, be used to cast the bullet train back end cover for motor, the weight percent of its each component is: Mg:4.35%, Cu:0.35%, Ti:0.235%, Fe:0.09%, Si:0.085%, surplus is Al, will carry out casting processing after its fusing equally, and the gained foundry goods is heat-treated on request, promptly obtain the back end cover for motor foundry goods of moulding, sample presentation detects through state-run 307 factory physical and chemical testing centers, and detected result is as follows: tensile strength Rm:209Mp, lower yield strength R _P02: 115Mp, hardness HB:63.3, unit elongation A:11.6%, institute's measured motor rear end cap cast properties all meets the requirements, and especially unit elongation has satisfied the requirement that reaches more than 10%, judges that foundry goods is qualified.

In the technological process of the described employing aluminum magnesium alloy of above embodiment as raw material casting electric motor end cap, external mold adopts metal pattern, internal mold to adopt CO ₂The sand mold mould, be baked to 200 ℃～350 ℃ before the casting, and spray titanium dioxide coating, take the vertical type casting to produce, six vertical feeding of dead head, in sand mold, establish rising pouring, guarantee the moulding of six ingate quick and stable, the liquid that prevents to cast produces to splash and impacts and eddy current, the upper strata takes the hole irrigation riser feeding to help foundry goods to solidify in order, casting system adopts open, and pouring temperature is strict to be controlled, and guarantees 755 ℃ ± 15 ℃ insulations, cast in 710 ℃～740 ℃ scopes, prevent owing to the alloy flowability difference causes the shrinkability of foundry goods big, easy to crack, easily produce oxide inclusion, defectives such as the surface is not bright and clean are watered earlier during casting soon, have arrived the rising head place and have changed into and watering slowly or the rising head hole irrigation, electric motor end cap foundry goods according to above casting technique operation gained, after testing, its chemical index, mechanical property, surface quality, casting dimensions etc. all reach technical requirement on design, and interior table machined surface does not have pore, burning into sand, casting flaws such as crackle.

In this aluminum magnesium alloy, Al is a main component, original Al of 99.7% purity that adopts is as raw material, but the alloy of making is after casting, and the gained foundry goods does not reach requirement, mainly is that unit elongation differs greatly, generally can only reach 2%～4%, for this reason, the applicant is through repeatedly research trial, prepares burden into 99.9% raffinal voluntarily as the main raw material of making aluminum magnesium alloy; Mg is main solution strengthening element, can improve the mechanical property of alloy, improve intensity and toughness, but the content of Mg also will be controlled well, only take suitable content, the alloy that melting obtains just has higher unit elongation, and the present invention is controlled at the weight percent of Mg in 3.8%～4.5% scope for this reason, has reached requirement; Cu also plays the solution strengthening effect in alloy, improve intensity, but can reduce unit elongation, but add the speed that a spot of Cu can significantly reduce the diffusion and the formation " group " of Mg atom, help obtaining high unit elongation by thermal treatment, therefore the content of Cu is chosen in 0.3%～0.4% scope, can increase tensile strength; Ti combines with Al, the non-spontaneous crystallization core in the time of can becoming the liquid metal crystallization, thus can improve plasticity toughness by crystal grain thinning, the content span of control is 0.2%～0.25% preferably; And Fe and Si exist as impurity, can reduce the obdurability of alloy, cause mechanical properties decrease, therefore need strict control, and the total content of general Fe+Si should be below 0.2%.

In the making of above-described rafifinal, all change the vessel of all contact aluminium liquid into the stainless steel making, the content of making every effort to make iron add silicon is controlled at below 0.2%, strict control impurity component, and the titanium that suitably adds 0.2%wt～0.25%wt content in aluminium liquid increases the plasticity and the toughness of aluminium.

The melting technology of aluminum magnesium alloy is as follows: first preheated crucible to 500 ℃～600 ℃, add red copper, aluminium ingot (adding 1/3 in advance) also adds an amount of special-purpose insulating covering agent HGQ-1, replenish remaining aluminium ingot midway, agitation as appropriate allows copper melt fully, liquid level covers and does not show money or valuables one carries unintentionally, slagging-off in the time of 780 ℃～810 ℃, be pressed into refining agent HGF-1 with bell jar, the gas that produces by reaction reaches the slagging-off effect of degassing, for reducing the loss, magnesium adds at last, add and fashionablely should note: magnesium ingot can be divided into fritter, can shorten the reaction times, avoid the slag parcel, add fashionablely, prevent that magnesium from burning because of burning-point is low with aluminium foil parcel.

The thermal treatment process of aluminum magnesium alloy: carry out solution treatment at 530 ℃, the time is 4 hours, and at 30 ℃～60 ℃ quenching-in water, 200 ℃ of timeliness, the time is 4 hours, the air cooling of coming out of the stove then then.

The foregoing description only is explanation technical conceive of the present invention and characteristics; its purpose is to allow the personage that is familiar with this technology can understand content of the present invention and is implemented; can not limit protection scope of the present invention with this; all equivalences that spirit is done according to the present invention change or modify, and all should be encompassed in protection scope of the present invention.

Claims

1. aluminum magnesium alloy, it is characterized in that: the weight percent of each component is: Mg:3.8%～4.5%, Cu:0.3%～0.4%, Ti:0.2%～0.23%, Fe: Si≤0.1% :≤0.1%, surplus is Al.