压铸条件下过共晶铝硅合金P变质的必要性

在铝合金压铸生产过程中,Al-P中间合金变质处理和压力铸造工艺都能够使过共晶铝硅合金中的初晶硅晶粒细化.探讨Al-P中间合金变质处理,分别在压铸工艺条件下和普通金属型条件下,对过共晶Al-15Si合金组织的不同影响.试验表明,压铸条件下未经Al-P变质的和经Al-P变质的Al-15Si合金与金属型条件下未经Al-P变质的Al-15Si相比,初晶Si尺寸分别减小50%和75%左右;在相同的压铸工艺条件下,Al-P变质后Al-15Si合金初晶Si尺寸,比未经过Al-P变质的Al-15Si合金初晶Si尺寸减小40%左右.论证了在Al-Si系过共晶铝合金压铸件生产过程中,Al-P中间合金进行变质处理的必要性.

P Modification on Hypereutectic Die Casting Al-Si Alloy

Both master alloy and die casting technology can refine the grain size of primary Si in hypereutectic Al-Si alloy in die casting. The effects of Al-P master alloy on the microstructures of hypereutectic Al-5Si alloy in die casting and in metal mold casting were approached. It is revealed that compared with microstructure of hypereutectic Al-Si alloy without Al-P master alloy modification in metal mold casting, the grain size of primary Si phase without Al-P master alloy modification is reduced by 50% while with Al-P modification is decreased by 75% in die casting. Compared with that of the alloy without Al-P modification in die casting, the primary Si size with Al-P modification in die casting is decreased by 40%. It is necessary to modify the hypereutectic Al-Si alloy by Al-P modifier in die casting.