AZ31B镁合金的铸轧组织及其相关变形机制  

Microstructures of twin-roll cast AZ31B Mg alloy and its deformation mechanism

作　　者：娄花芬[1] 汪明朴[1] 唐宁[1] 李周[1] 郭明星[1] 雷前[1] 

机构地区：[1]中南大学材料科学与工程学院

出　　处：《中国有色金属学报》2008年第9期1584-1589,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家十一五科技支撑计划资助项目(2006BAE04B02)

摘　　要：利用金相显微镜、透射电子显微镜对AZ31B镁合金铸轧板坯的微观组织进行研究。结果表明:铸轧AZ31B镁合金板坯主要由α-Mg基体、枝晶间Mg17Al12共晶体和弥散分布的细小析出相组成,铸轧对晶粒的细化效果不明显;板坯在铸轧过程中经历一定的塑性变形,且变形多分布于板材表层;塑性变形在合金中产生大量的位错及位错胞的同时,也产生一定数量的孪晶;经孪生改变晶体取向后的晶粒会在适合的条件下发生滑移变形,孪生和滑移的协同作用使孪晶和位错共存、孪晶中位错的产生和孪晶的变形;铸轧时的塑性变形和高温还导致回复和再结晶的发生。The microstructures of AZ31B magnesium alloy twin-roll cast sheet were studied by metallographic microscope and TEM. The results show that the sheet is made up of a-Mg matrix, interdendritic Mg17A12 eutectic and some dispersive fine precipitates. Sheet undergoes biggish plastic deformation, and the deformation distributes more near sheet surface than interior. A mass of dislocations and dislocation cells form during plastic deformation while some twins form simultaneously. After twining, the grain orientations change, and then they will slip on suitable condition. This process leads the formation of dislocations in twins and deformation of twins. The recovery and recrystallization reduce during twin-roll casting because of the plastic deformation and high temperature.

关 键 词：AZ31B合金 双辊铸轧 孪生 位错滑移 

分 类 号：TG146.2[一般工业技术—材料科学与工程]