AZ31-0.5Sr-1.5Y热变形行为分析

Deformation behavior of alloy AZ31-0.5Sr-1.5Yat elevated temperature

采用Gleeble-1500D型热模拟试验机，在变形温度为250～450℃，应变速率为0．01～1S，最大应变量为0．85的条件下，对AZ31-0．5Sr-1．5Y进行单向热压缩实验。对材料的热变形行为和热加工性能进行了研究，建立了合金热变形过程中的本构方程和热加工图，并结合金相显微组织观察对加工图进行了分析。结果表明：Az31-0．5Sr-1．5Y在热变形过程中的稳态流变应力可用双曲正弦函数关系式进行描述，其应变激活能为186．83kJ／mol，热加工图分析表明，在本实验条件下，当真应变为0．6时，材料存在着非稳态流变区，其温度为250～300℃，应变速率为0．3～1S，材料的最佳热加工工艺参数为：温度300～400℃，变形速率0．01～1s。

The uniaxial hot compression test with Gleeble-1500D thermal simulator is performed on AZ31 0.5Sr-1.5Y alloy in the temperature range of 250-450℃ and stain rates of 0.01-1 s-1 with the maximum deformation degree of 0.85. The hot deformation behavior and hot workability of the alloy are studied. The constitutive equation and processing map of the alloy are established and studied by optical microstructure observation. The results show that the steady flow stress of AZ31-0. 5Sr-1. 5Y deforms at elevated temperatures can be described by the hyperbolic sine constitutive equation, and the activation energy is about 186.83 kJ/mol. After analyzing the hot processing map, at the true strain of 0.6, there is one unsafe deformation zone in the deformation temperature range of 250-300℃ and the strain rate range of 0.3-1 s 1 The optimal processing parameters obtained in the present work are the temperature range of 300-400℃ and strain rates of 0.01-1 s-1.