喷射成形7055铝合金热变形行为模拟

摘要

The hot deformation behavior of spray formed 7055 aluminum alloy was investigated in this paper.Hot compression deforma-tion was performed on Gleeble-3500 thermal-mechanical simulator at strain rate of 0.001 -5s -1 and deformation temperature of 573-723K.The result shows that the flow stress of spray formed 7055 aluminum alloy is increased with the increasing of strain rates,while decreased with the increasing of the deforming temperature.The maximum temperature rising induced by deformation heat is 25K dur-ing the test at strain rate of 5s -1 ,and the corrected flow stress is 20MPa higher than measured value.A flow stress constitutive equa-tion is constituted based on Arrhenius hyperbolic sine function containing the Z parameter,and the hot deformation activation energy is 146.91 kJ·mol -1 .The average absolute relative error (Er )is introduced to evaluate the performance of the developed constitutive e-quation.The value of Er is 2.89% ,which proves the developed constitutive equation can accurately predict the flow stress of the spray formed 7055 aluminum alloy.%为研究喷射成形7055铝合金的热变形行为，在应变速率为0．001～5 s －1、变形温度为300～450℃、工程应变量为50％条件下，在 Gleeble-3500热-力模拟试验机上进行热压缩实验。结果表明：喷射成形7055铝合金的流变应力随应变速率的增大而增大，随变形温度升高而减小。在应变速率为5s －1时由变形热引起的温升达25℃，经修正流变应力比实测值增高20 MPa。采用包含 Z 参数的 Arrhenius 双曲线正弦本构方程可准确描述喷射成形7055铝合金的热变形流变应力行为，变形激活能为146．91 kJ·mol －1。所建本构方程的平均相对误差（Er ）为2．89％，说明可准确预测喷射成形7055铝合金的热变形流变应力。