Microstructure of asymmetric twin-roll cast AZ31 magnesium alloy  

AZ31镁合金异步铸轧板的显微组织(英文)

作　　者：赵虎[1,2] 何良菊[1] 李培杰[1,2] 

机构地区：[1]清华大学新材料国际研发中心,北京100084 [2]清华大学机械工程系,北京100084

出　　处：《Transactions of Nonferrous Metals Society of China》2011年第11期2372-2377,共6页中国有色金属学报（英文版）

基　　金：Project (2006BAE04B02) supported by the National Key Technology R&D Program during the 11th Five-Year Plan of China

摘　　要：The microstructural distribution along thickness of asymmetric twin-roll cast AZ31 magnesium alloy slab was investigated. It was found that the microstructure along the thickness of the slab was significantly inhomogeneous. There were many deformed bands with flow form near the upper surface of twin-roll cast plate. Very few deformed bands could be seen in the central part of the plate where the dendrites were thick. Fine dendritic structures dominated near the lower surface of the twin-roll cast strip. It is concluded that the shear strain caused by linear velocity difference between surfaces of upper and lower rolls results in the deformed bands of the twin-roll cast slab. Aluminum, zinc and manganese segregate to the boundary of dendrites, while silicon distributes inside the α-Mg solid solution.研究AZ31镁合金异步铸轧板坯沿厚度方向的显微组织分布。结果表明,板坯组织沿厚度方向具有较明显的不均匀性。在板坯的上表面附近存在较多的流线型变形带组织;在中心处观察不到变形带组织,枝晶臂较粗大;在板坯下表面附近枝晶组织较细密。板坯上表面附近的流线型变形带是由上、下铸轧辊表面线速度差产生的剪切应变而引起的。Al、Zn和Mn在枝晶晶界处发生偏聚,Si均匀分布在α-Mg固溶体内。

关 键 词：AZ31 magnesium alloy asymmetric twin-roll casting deformation bands PRECIPITATE 

分 类 号：TG339[金属学及工艺—金属压力加工]