(1. 重庆大学 机械传动国家重点实验室，材料科学与工程学院，重庆 400044；
2. 重庆大学 国家镁合金工程技术研究中心，材料科学与工程学院，重庆 400044；
3. 重庆先进材料研究中心，重庆科学技术研究院，重庆 401123)
摘 要: 研究微量(0.2%，质量分数)Ce和Ca对AZ31合金组织演变和成形性能的影响，期望通过改善组织和织构开发低成本高成形性能的镁合金。结果表明：Ce和Ca可以使挤压态AZ31板材再结晶晶粒更加均匀细小；Ce和Ca可以弱化轧制退火态板材的基面织构，Ca会使AZ31板材的基面织构基极向横向发散，同时，Ce和Ca还能使AZ31板材的r值和各向异性降低；Ce和Ca可以大幅提高AZ31合金板材的室温成形性能，Mg-3Al-1Zn-0.2Ce-0.2Ca合金薄板的基面织构强度为3.2，r值为1.05，Δr值为0.04，其Erichsen值达到6.0 mm。织构的改善主要是由于合金元素引起的滑移系的改变，板材各向异性的降低与其织构的改善密切相关，室温成形性能的提高可以归因于织构的改善、较小的r值和较大的n值。
关键字: 镁合金；组织演变；成形性能；织构；微合金化
（1. State Key Laboratory of Mechanical Transmission, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. National Engineering Research Center for Magnesium Alloys，Chongqing University, Chongqing 400044, China;
3. Chongqing Research Center for Advanced Materials, Chongqing Academy of Science & Technology, Chongqing 401123, China）
Abstract:The effects of trace (0.2%, mass fraction) Ce and Ca on microstructure evolution and formability of AZ31 alloys were investigated desiring to develop low-cost and high-formability magnesium alloys by improving the microstructure and texture. The results reveal that Ce and Ca can make the recrystallize grains of the extruded AZ31 sheets more uniform and smaller. Ce and Ca can weaken the basal texture of the rolled and annealed sheet, Ca can cause the basal pole of AZ31 sheets to spread towards TD, Ce and Ca also decrease the r value and anisotropy of AZ31 sheets. Ce and Ca greatly improve the room temperature formability of AZ31 alloy sheets, the basal texture of Mg-3Al-1Zn-0.2Ce-0.2Ca sheets is 3.2, r value is 1.05, Δ r value is 0.04, and its Erichsen value is 6.0 mm. The modified texture is mainly due to the change of the slip systems caused by the alloying elements, the reduction of sheet anisotropy is closely related to the modified texture, and the improvements at room temperature formability of the alloys can be attributed to the modified texture, smaller r values and larger n values.
Key words: magnesium alloy; microstructure evolution; formability; texture; microalloying
