摘要
The effects of minor contents of Zr and Sc on the microstructures and mechanical properties of Al-Mg-Si-Cu-Cr-V alloy were studied. The results show that the effects of minor Zr and Sc on the as-cast grain refinement in the ingots, the improvement in the strength of the as-extruded alloys and the restriction of high angle grain boundaries in the aged alloys can be sorted as Al3ScAl3 （Zr,Sc）Al3Zr. None of them could stop the nucleation of recrystallization, but Al3 （Zr,Sc） phase is a more effective inhibitor of dislocation movement compared to Al3 Sc in the aged alloys. Compared with the mechanical properties of the aged alloy added only 0.15% Sc, the joint addition of Zr and Sc to the alloy leads to a very slight decrease in strength with even no cost of ductility. Taking both the production cost and the little bad influence on mechanical properties into consideration, an optimal content of Zr and Sc in the Al-Mg-Si-Cu-Cr-V alloy to substitute 0.15% Sc is 0.13% Zr＋0.03% Sc.
研究微量Zr和Sc对Al-Mg-Si-Cu-Cr-V合金显微组织与力学性能的影响。结果表明:微量元素Zr和Sc对铸态晶粒细化、合金挤压态强度的提高以及对时效态合金中大角度晶界迁移的阻碍作用,由大到小依次为:Al3Sc>Al3(Zr,Sc)>Al3Zr。它们均无法阻止再结晶形核,但对于时效态合金,Al3(Zr,Sc)相对于位错运动的阻碍比Al3Sc相更为明显。与单一添加0.15%Sc合金的时效态进行比较,复合添加Zr和Sc仅会轻微降低合金的强度而对塑性没有影响。综合考虑合金生产成本以及对力学性能的轻微损害等因素,在Al-Mg-Si-Cu-Cr-V合金中复合添加0.13%Zr和0.03%Sc是替代0.15%Sc的最佳方式。
基金
Projects(N110609002,N110408005)supported by the Fundamental Research Funds for Northeastern University,China
