AA2195铝锂合金的热变形行为

Hot deformation behavior of AA2195 alloy during isothermal compression at elevated temperature

通过Gleeble-3500热模拟实验机上进行热压缩实验,研究了变形温度为400~500℃,应变速率为0.01~10s^(-1)时2195铝锂合金的热变形行为。通过金相显微镜研究了热变形中显微组织的演变。研究结果表明,该合金流变应力随变形温度的升高而降低,随应变速率的提高而增大。该合金流变应力可采用Zener-Hollomon参数来描述,在获得流变应力σ解析表达式中A=7.08018×1012 s^(-1)、α=β/n1=0.01473、n1=5.42929,其热变形激活能为Q=190.27kJ/mol。热加工图表明AA2195铝锂合金适宜加工区为400~430,442~473℃,应变速率为0.01~0.2s^(-1)以及温度范围为477~500℃,应变速率为0.01~0.3s^(-1)的区域。

The hot deformation behavior of 2195aluminium-lithium alloy during hot compression deformation was studied with the temperature range from 400 to 500℃,and the strain rate range from 0.001 to 10s^-1 by isothermal compression test at Gleeble-3500 thermal mechanical simulator.The microstructure evolution of samples were characterized using the optical microscopy（OM）.Processing maps at various strain for 2195 alloy were developed using dynamic materials model（DMM）theory.The results show that the flow stress affected by temperature and strain rate,it decreases with increasing temperature,increases with increasing strain rate.The flow stress of 2195 alloy during high temperature deformation can be expressed by a Zener-Hollomon parameter.The values of A,a and n1 in the analytical expressions of flow stress（σ）are fitted to be 7.08018×10^12s^1,0.01473 and 5.42929.The hot deformation activation energy of 2195 alloy during hot deformation is 190.27kJ/mol.The optimum hog-working condition for AA2195 aluminum alloy is determined to be in the temperature range of 400-430℃,442-475℃under strain rates of 0.01-0.2s^-1 and 477-500℃under strain rates of 0.01-0.3s^-1.