(1. 湖南科技大学 机电工程学院，湘潭 411201；
2. 中南大学 材料科学与工程学院，长沙 410083；
3. 重庆大学 国家镁合金工程技术中心，重庆 400044)
摘 要: 对挤压态AZ31镁合金试样沿挤压方向截取试样(0°试样)和垂直于挤压方向截取试样(90°试样)，并分别进行变形量为12%的冷锻变形，在320 ℃下保温不同时间进行再结晶退火。利用金相显微镜和背散射电子衍射技术研究AZ31镁合金的微观组织演变。结果表明：经冷锻变形的0°试样，内部存在大量细小碎晶、{ }-{ }、{ }和{ }-{ }等孪晶，平均小角度取向差频率为0.031，硬度由57HV增至71.3HV，随后的再结晶退火可显著细化原始混晶组织；经冷锻变形的90°试样，内部含有少量的{ }-{ }二次孪晶，平均小角度取向差频率为0.017，硬度由57HV增至69.3HV，再结晶退火时，与0°试样对比，静态再结晶开始及结束时间均被推迟。
关键字: AZ31镁合金；冷锻；静态再结晶；织构
（1. College of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
3. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China）
Abstract:0 ° and 90° samples of extruded AZ31 magnesium alloys were obtained from cutting along the extrusion direction and perpendicular to the extrusion direction, respectively, and 12% cold forging deformation was carried out on them, then recrystallization annealing tests were performed at 320℃ for different durations. The microstructure evolution of AZ31 magnesium alloys was investigated by metalloscopy and electron backscatter diffractometry. The results show that in 0° sample there are a large amount of tinny broken grains, { }-{ }, { } and { }-{ }, the average frequency of low angle grain boundary is 0.031, and the hardness increases from 57HV to 71.3HV. Besides, original mischcrystal structure can be refined obviously by subsequent recrystallization annealing. As for 90° sample, only a few of { }-{ } double twins come out, the average frequency of low angle grain boundary is 0.017, and the hardness increases from 57HV to 69.3HV. By comparison with that of 0° sample, the starting and ending times of static recrystallization for 90° sample are delayed during the recrystallization annealing process.
Key words: AZ31 magnesium alloy; cold forging; static recrystallization; texture
