Si对往复挤压Mg-Al-Si再结晶组织和力学性能的影响

Effects of Si on recrystallized microstructure and mechanical properties of Mg-Al-Si alloys processed by reciprocating extrusion

利用往复挤压细化了Mg-4Al-2Si、Mg-4Al-4Si和Mg-6Al-6Si合金组织,分析了Si含量对合金组织和力学性能的影响。结果表明,随着Si含量增加,基体晶粒和Mg2Si颗粒粗化,拉伸强度降低。基体组织细化受Mg2Si相的形态和均匀性控制,为再结晶和Mg2Si相阻碍晶界移动的复合机制,力学性能主要由基体晶粒尺寸决定。

Microstructure of Mg-4Al-2Si,Mg-4Al-4Si and Mg-6Al-6Si alloys were refined by reciprocating extrusion,and effects of Si content on the recrystallized microstructure and mechanical properties of the alloys were investigated.The results show that with increasing Si content the matrix grains and Mg2Si particles are coarsened during recrystallization,and hence tensile strengths of the alloys decreases.The matrix refinement is attributed to a combination mechanism of dynamic recrystallization and the restraining effect of Mg2Si particles on grain growth,which is controlled by the morphology and distribution of Mg2Si particles.The mechanical properties of the extruded alloys depend mostly on matrix grain size.