复合添加Nd与B对AZ91镁合金组织和力学性能的影响

摘要

This paper presents the effects of B and Nd combined addition on microstructure and mechanical properties of AZ91 alloy. SEM results show that B and Nd combined addition significantly refines the grain size of α-Mg and β-Mg17Al12 precipitates, Grain refinement is due to the presence of AIB2 particles, nucleants for Mg grains, and Nd addition refines β-Mg17Al12 phases, Al2Nd and Mg12Nd exist on the intermetallic surface. They have high thermal stability and significantly improve mechanical properties of magnesium alloys. Normal temperature mechanical properties of AZ91 alloys are greatly improved due to grain refinement and the presence of Al2Nd and Mg12Nd.%研究了复合添加Nd和B对AZ91镁合金的微观组织和力学性能的影响。结果表明，复合添加B和Nd明显细化了α-Mg和β-Mg17Al12相。晶粒细化主要源自于AlB2相作为α-Mg的异质形核衬底，添加的Nd细化了β-Mg17Al12相。扫描电镜分析表明，Al2Nd和Mg12Nd主要分布在晶界上，并且对合金力学性能起到了重要的促进作用。由于晶粒细化及热稳定相Al2Nd和Mg12Nd的存在，AZ91镁合金的常温力学性能得到大大改善。