Nowadays,Industrial die casting aluminum alloy mainly include Al-Si,Al-Mg,Al-Si-Cu,Al-Si-Mg.Die casting aluminum alloy featured in high strength,corrosion resistance,machining ability and recyclable.They are wildly used in automobile,aerospace and electronics industry.With development of automobile industry,production of aluminum alloy increase by 13% per year.
Normal die casting aluminum parts are not suitable to heat treatment,which affect improvement of properties of aluminum die casting parts.Currently,die casting parts wildly used in structure of automobile.However,it can not meet strict requirement in automobile industry by normal aluminum die casting parts.Therefore,researchers have been studying new aluminum alloy in two main aspects.One is to add element into aluminum alloy and the other is to make new composition of aluminum alloy.
Al-Si-Cu own good casting ability and medium strength.Typical Al-Si-Cu are AlSi8.5Cu3.5 and AlSi11Cu3.AlSiCuRE featured in good fluidity,wear resistance,air tightness,machining ability.It is much better than other Al-Si-Cu alloy and wildly used in gear box,engine housing,valve,pistol,wheel rim etc.ADC12.1R made by enhancing composition of ADC12 and become better casting and machining ability.
Al-Si-Mg own better hot resistance,fatigue resistance.Especially,A357 wildly used in aerospace and military.Both Silafont-36 and Castasil-37 are high strength aluminum alloy and can be used in very tough condition like structure of automobile.Castasil-37 has 12% elongation and yield strength of 120Mpa and can be directly used for complex geometry automobile parts without solution treatment.For AlSi12,it is suitable to thin wall and complex geometry die casting parts.The disadvantage of AlSi12 is poor strength and machining ability,which limit its usage.By adjust composition of AlSi12,the elongation increase by 14.17% and casting ability improve nicely.
Al-Mg is a little difficult for die casting since Mg add into alloy.It mostly used in parts which request special surface and corrosion resistance and lower strength.Magsimal-59 belong to AlMg5Si2 with low Cu,Zn and Fe.It own high strength but can not be heat treated.
Currently,Some new aluminum alloy are under studying.They are semi-solid Al-Si-Mg,Al-Cu,Al-Fe,Al-Si-Fe.
By optimizing composition of die casting aluminum alloy,we have improve properties of alloy.However,it still have lots of work to do for die casting aluminum alloy to meet more and more requirement in different industry.