(北京有色金属研究总院 有色金属材料制备加工国家重点实验室，北京 100088)
摘 要: 在变形温度为250~400 ℃，应变速率为0.002~1 s−1时，在Gleeble−1500D热模拟试验机上对不同状态(铸态、(410 ℃，4 h)、(410 ℃，16 h))的AZ80镁合金进行热压缩变形行为研究；根据实验结果建立热加工图，并利用热加工图分析均匀化程度对合金再结晶能力的影响。结果表明：随着均匀化程度的提高，相同条件下的峰值应力随之提高，发生动态再结晶的温度和应变速率逐渐提高；410 ℃、16 h处理合金的再结晶能力明显强于其他2种状态合金的，在(400 ℃、0.01 s−1)时动态再结晶晶粒更加均匀、细小，晶间无条带状共晶组织；对AZ80镁合金在大变形之前进行完全均匀化处理有利于动态再结晶组织的控制，其最佳变形温度范围为380~400 ℃，变形速率范围为0.002~0.1 s−1。
关键字: AZ80镁合金；均匀化处理；热压缩；热加工图；显微组织
AZ80 magnesium alloys with processing map
（State Key Laboratory for Fabrication and Processing of Nonferrous Metals,
Beijing General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:The hot deformation behaviors of AZ80 magnesium alloys at different states (as-cast, (410 ℃, 4 h) (410 ℃, 16 h)) in the temperature range of 250−400 ℃ and strain rate range of 0.002−1 s−1 were investigated by hot compression test on a Gleeble−1500D simulator. Based on these data, three processing maps were developed to assist in the analysis of the influence of homogenization on the deformation properties of AZ80 alloys. The results show that, with increasing the degree of uniformity, the peak stresses are enhanced at the same temperature and strain rate, the strain rate and temperature of the dynamic recrystallization are gradually raised, and the recrystallization ability of the alloy after homogenization at 410 ℃ for 16 h is the best among three alloys; the grains of alloys are more even and more finer after deformation under the condition of 400 ℃ and 0.01 s−1, without visible branded eutectic structure in the intergranular. Therefore, complete homogenization before large deformation for AZ80 Mg-alloys is in favor of the microstructure control of dynamic recrystallization, and the optimum ranges of deformation temperatures and rates are 380−400 ℃ and 0.002−0.1 s−1, respectively.
Key words: AZ80 magnesium alloy; homogenization; hot compression; processing map; microstructures
