基于单向拉试验5A90铝合金超塑性能试验研究  

Experimental Research on Superplastic Performance of 5A90 Alloy Based on One-way Tensile Test

作　　者：毕宝鹏 王勇[1] 孙梦莹[1] 

机构地区：[1]北京机电研究所,北京100083

出　　处：《热加工工艺》2015年第8期105-109,共5页Hot Working Technology

基　　金：国家航空航天基金支持(2013DFR70860)

摘　　要：采用等应变速率拉伸法研究了温度和应变速率对5A90合金超塑性力学性能的影响。结果表明：5A90铝合金最佳变形温度是400℃,在此温度下,不同应变速率条件下,可以获得较大的伸长率,最大伸长率为193.6%;在变形温度为375℃～500℃时,应变速率对5A90铝合金的流变应力及抗拉强度有显著影响,流变应力及抗拉强度随应变速率升高而增大。在同一应变速率下,5A90铝合金流变应力水平随着变形温度的提高而降低。另外,基于Backofen本构方程,对5A90铝合金在不同温度状态下的强化规律进行了分析,结果表明,随变形温度逐渐升高,应变速率敏感性指数先减小后增大,最后得到5A90铝合金最佳超塑性参数为：T=400℃,ε=0.0005s-1。The influence of temperature and strain rate on the superplasticity mechanical behavior of 5A90 alloy were investigated by constant strain-rate tensile method. The results show that the best deformation temperature for 5A90 alloy is 400 ℃ and at this temperature, under different strain rate conditions, the larger elongation can be obtained, then, the maximum elongation is 193.6%. When deformation temperature of 375-500 ℃, the effect of strain rate on flow stress and tensile strength of the flow stress were studied. The flow stress and tensile strength of the alloy increases with the increase of strain rate. Under the same strain rate, and the flow stress level decreases with the increase of deformation temperature. In addition, the strengthening law of 5A90 aluminum alloy at different temperatures were analyzed based on Backofen constitutive equation. The results show that with the rising of deformation temperature, the strain rate sensitivity index increases after first decreasing, and finally the best superplastic parameters for 5A90 alloy is obtained ,which is T=400 ℃, ε=0.0005s-1

关 键 词：5A90铝锂合金 超塑性 流变应力 本构方程 

分 类 号：TG306[金属学及工艺—金属压力加工]