微量Sc对5A01铝合金性能与显微组织的影响

Effect of Micro Sc on Microstructure and Properties of 5A01 Aluminin Alloy

研究了在5A01铝合金基础上添加0.2％Sc和0.3％Sc后合金的显微组织、力学性能、腐蚀性能及焊接性能。结果表明,微量Sc的加入,初生Al_3Sc或Al_3(Sc,Zr)粒子可成为有效的非均质晶核,大大地细化合金的铸态晶粒,次生Al_3Sc或从Al_3(Sc,Zr)粒子能有效地钉扎位错和亚晶界,稳定亚结构并强烈抑制合金的再结晶。因此,加入Sc后的试验合金基体及焊接强度提高,腐蚀性能和焊接性能与5A01铝合金相当,甚至更好。

The microstructure, mechanical properties, corrosion resistance and weldabilities for 5A01 alloy with Sc addition by 0.2wt.% and 0.3wt.%, respectively, were invesigated. The results showed that, the primary Al3Sc of Al3(Sc, Zr) particles effetively functioned as the heterogeneous nucleation sites, and hence refined the as-casted grain sizes signifincantly. In addition, the secondary Al3Sc of Al3(Sc, Zr) particles strongly pinned up the dislocations and sub-grain boundaries, resulting in a stable sub-structure and highly ingibiting the recrystalliztion of the alloy. It could be concluded that, thd Sc addition improved the tensile strength of both matrix and weldament, with the corrosion resistance and weldability keepiing comparable with or even better than that of non Sc added 5A01 alloy.