同时添加钪、锆对Al-10Mg合金再结晶机制的影响

Effect of Complex Addition of Sc and Zr on Dynamic Recrystallization Mechanism of Al-10Mg Alloy

利用电子背散射衍射(EBSD)和透射电子显微镜(TEM)研究了Al-10Mg及Al-10Mg-0.1Sc-0.1Zr合金在热压缩过程中的组织演变及动态再结晶机制。结果表明:同时添加Sc、Zr能够明显细化Al-10Mg合金的铸态晶粒,热处理后,Sc、Zr能够形成与α-Al基体共格的Al3(Sc,Zr)相,这些沉淀相能够提高合金的热变形抗力;在变形过程中,Al3(Sc,Zr)相能够钉扎位错运动、降低晶界及变形带处的位错密度,使位错在沉淀相周围聚集,因而改变了Al-10Mg合金内部位错增殖与湮灭的过程、进而使Al-10Mg合金动态再结晶方式由不连续动态再结晶(DDRX)转变为连续动态再结晶(CDRX)。

The microstructure evolution and recrystallization mechanism of compressed Al-10 Mg alloy with and without addition of Sc and Zr have been investigated by electron back-scattered diffraction(EBSD)and transmission electron microscope(TEM).Results show that original grain is refined through Al3(Sc,Zr)precipitation.Also,flow stress can be increased.In the presence of Al3(Sc,Zr)precipitation,dislocation motivation is impeded,concentration of dislocation is decreased in grain boundary and deformation band;accumulation and annihilation of dislocation is thus affected.Recrystallization grain is formed through rotation of subgrain in Al-10 Mg-Sc-Zr alloy.Afterwards,recrystallization mechanism of Al-10 Mg alloy is changed from discontinuous dynamic recrystallization(DDRX)into continuous dynamic recrystallization(CDRX).