熔体过热处理对含1.1%Ni的Al-11%Si合金中Zr、Ti、Mg和RE作用的影响

Influence of Melt Overheating Treatment on Effects of Zr,Ti,Mg and RE in Al-11%Si Alloy with 1.1%Ni

对Al-11Si-1.1Ni-0.2Fe合金采用过热处理,考察了过热处理对强化元素Zr、Ti、Mg和变质元素RE对合金所起的作用的影响。试验结果证明,1 050℃的过热处理能够极大地细化合金中共晶硅使之成为颗粒状,使合金的抗拉强度和伸长率得到很大程度的提高;同样是经过1 050℃的过热处理,看不出Zr、Ti对合金的细化作用,也看不出RE对共晶硅的变质作用;但Mg的强化非常显著,加入Mg以后能使合金的铸态抗拉强度提高14.4%,过热处理态抗拉强度提高100%。

The Al-11Si-1.1Ni-0.2Fe alloy was overheated at different temperatures, and the influence of the overheating treatment on the effects of Zr, Ti, Mg and RE in the alloy was tested. The results show that overheating treatment at temperature 1 050 ℃ could improve the tensile strength and the elongation of the alloy, but the grain refinement effect of Zr and Ti on the alloy were not displayed, the modification effect of RE on eutectic silicon was also not found. Mg displays a remarkable strengthening effect on alloy, the tensile strength increased by 14.4% at as-cast state and 100% after heat treatment.