轧制镁合金超塑性和超塑胀形  

Superplasticity and superplastic bulging capability of rolled magnesium alloy

作　　者：于彦东[1] 张凯锋[1] 蒋大鸣[1] 郑海荣[1] 王长丽[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院

出　　处：《中国有色金属学报》2003年第1期71-75,共5页The Chinese Journal of Nonferrous Metals

摘　　要：对轧制态MB15镁合金进行了超塑性拉伸实验 ,结果表明 :晶粒尺寸为 5 .9μm的MB15镁合金板材 ,在温度为 5 73K、初始应变速率为 5 .5 6× 10 -4s-1的变形条件下 ,获得的最大延伸率为 30 9% ,应变速率敏感指数为0 .34;当真应变为 0 .3时 ,试样的晶粒尺寸为 4 .5 μm ,说明在拉伸初始阶段轧制镁合金可以获得细晶组织 ,同时发生了部分动态再结晶。利用扫描电镜观察断口发现典型的超塑性空洞形貌特征。通过胀形实验可以看出 ,该镁合金板材的超塑成形性能好 。Superplasticity of a rolled magnesium alloy Mg-Zn-Z r was investigated at 573 K and a strain rate of 5.56×10 -4 s -1 . The m aximum elongation is 309% and the strain rate sensitivity exponent m is 0.34 . The grain size of the rolled magnesium alloy is 5.9 μm. However, the grain s ize of the specimen deformed to a true strain of 0.3 is 4.5 μm. The grain ref inement is attributed to dynamically continuous recrystallization during the ini tial stage of tensile test. SEM observation shows that the typical cavities are obvious in fracture surfaces of tensile samples after superplastic deformation. Finally, the successful superplastic gas pressure bulging forming experiment pro ves the satisfying superplastic forming capability of the alloy.

关 键 词：动态再结晶 气胀成形 镁合金 轧制 超塑性 超塑胀形 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG39[金属学及工艺—金属材料]