A356铝合金Al-5Ti-1B和Al-10Sr熔体处理遗传效应

通过重熔试验研究Al-5Ti-1B和Al-10Sr中间合金在A356熔体中的遗传效应。结果表明:A356合金经熔体处理后流动性较母材提高17.36%,T6处理后α-Al枝晶细化,二次枝晶间距仅为16.8μm,共晶硅圆整,抗拉强度达269 MPa、屈服强度203MPa、伸长率12.5%、硬度92 HBW。伴随重熔,细化变质效果逐渐衰退,熔体质量下降,以致力学性能和流动性下降。试验发现固溶后快淬可减小变质衰退带来的影响。

Heredity of modified A356 alloy by addition of Al-5Ti-1B and Al-10Sr master alloys after remelting treatment

Hereditation of Al-5Ti-1B and Al-IOSr master alloys on modified A356 alloy was studied by remelting experiments. The results show that fluidity of the modified A356 alloy increases by 17.36% after melting treatment compared with that of as-received A356 alloy. After T6 treatment for the modified A356 alloy by addition of Al-5Ti-1B and Al-10Sr master alloys,α-Al dendrite in the alloy is refined,and the secondary dendrite arm spacing is only 16. 8μm. The eutectic silicon in the modified A356 is round and spheroidal,and its tensile strength reaches 269 MPa,yield strength reaches 203 MPa,elongation percentage is about 12. 5% and Brinell hardness is 92 HBW. As the increasing of remelting time,effect for refinement and metamorphism of the master alloy gradually declines,and the fluidity of the melt and the mechanical properties of the modified A356 alloy decreasea. Fast-quenching under liquid-N2 after solution treatment can reduce the effect of metamorphism declining.