喷射沉积超高强铝合金唯象本构方程材料常数应变补偿分析

Phenomenological constitutive model of spray deposited ultra high strength aluminum alloy based on strain compensation

基于热模拟试验,在获得变形温度为523~723 K（间隔50 K）,应变速率为0.001、0.01、0.1、1 s-1喷射沉积超高强铝合金真应力-真应变数据的基础上,根据Arrhenius唯象本构方程计算出真应变为0.1、0.2和0.3时的材料常数（n、β、α、Q和ln A3）。结果表明,不同真实应变下的材料常数不同。根据真应变为0.1~0.6（间隔0.1）下的材料常数计算结果,采用回归分析的方法,进行材料常数应变补偿回归分析。材料常数n、β、α、Q和ln A3回归分析的可决系数为0.993 62、0.963 27、0.986 82、0.986 92和0.985 29,回归分析的拟合优度高,很好地反映出材料常数随真应变的变化规律。在此基础上建立了不同材料常数的应变补偿回归模型。

Hot compression tests of spray deposited ultra high strength aluminum alloy were conducted on the Gleeble-3500 under temperature range from 523 K to 723 K,at interval 50 K while the imposed constant true strain rates were 0.001,0.01,0.1 and1 s- 1. Using the true strain- true stress data,the materials constants（n,β,α,Q and ln A3）were calculated based on the Arrhenius phenomenological constitutive model. It can be clearly observed that the constants of different materials change with true strain. According to the values of constants（0.1-0.6,at interval 0.1）,the strain compensation for those constants was carried out using regression analysis method. The results show that the coefficients of determination of n,β,α,Q and ln A3are0.993 62,0.963 27,0.986 82,0.986 92 and 0.985 29,respectively,with higher goodness of fit. Regression analysis results present the influence of strain on material constants with good correlation and generalization. Based on the results,the regression models of constants were established.