变质处理晶粒细化对AZ91镁合金半固态组织演变的影响  

Effect of Modification on Semi-solid Microstructure Evolution of AZ91 Magnesium Alloy

作　　者：行舒乐[1] 袁森[1] 王武孝[1] 王强[1] 王欣欣[1] 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《铸造技术》2009年第4期514-517,共4页Foundry Technology

摘　　要：使用Nd、C2Cl6和Ca三种变质剂对AZ91镁合金进行变质处理,然后对晶粒细化后的坯料进行半固态重熔实验,将3种变质坯料及未变质AZ91镁合金坯料的半固态组织演化过程及演化速度进行了比较。结果表明,未变质AZ91镁合金坯料半固态演化速度最为缓慢,晶粒也较为粗大。Nd和C2Cl6变质后的AZ91镁合金坯料为细小的等轴晶组织,其半固态演化过程得以缩短,晶粒也更为细小。而Ca的加入并没有明显改善AZ91镁合金坯料的半固态演化速度,原因可能是Ca提高了AZ91镁合金共晶组织的热稳定性和熔点所致。AZ91 magnesium alloy were modified respectively with Nd,C2Cl6 and Ca ,and then were semi-solid remelted isothermally. The semi-solid microstructure evolution and evolutionary rate of modified AZ91 magnesium alloy and AZ91 magnesium alloy were studied. The results show that= the semi-solid microstructure evolution rate of AZ91 magnesium alloy is slower and the grains are bigger. The microstructure of AZ91 magnesium alloy billet modified with Nd and C2Cl6 are equiaxed grains, and the processes of microstructure evolution are shortened, the grains are finer too. But the evolutionary rate of AZ91 magnesium alloy modified with Ca on microstructure evolution is lower than Nd and C2Cl6, The possible reason is that thermal stability and melting point of AZ91 magnesium alloy modified with Ca are increased.

关 键 词：AZ91镁合金 变质处理 半固态重熔 组织演变 

分 类 号：TG146.22[一般工业技术—材料科学与工程]