粘塑性金属材料蠕变实验及流变模型研究

RESEARCH ON CREEP EXPERIMENTS AND RHEOLOGICAL MODEL OF VISCO-PLASTIC METAL MATERIALS

对固体金属材料Lc4铝合金、TC11钛合金及优质碳素结构钢(20#、35#)在高温下进行了多组蠕变实验,对电沉积镍薄膜在常温下进行了多组加、卸载和蠕变实验,根据实验曲线,采用修正的Burgers流变模型来描述这些材料的蠕变行为,建立了积分型蠕变本构方程和微分型应力应变本构关系,确定了蠕变积分核函数,并对由蠕变方程推导的理论结果和实验结果进行了比较,理论值与实验值吻合较好.同时,利用蠕变实验数据,求出了粘塑性材料本构方程中表征粘性性质的材料常数γ〈(F)〉,并对前者在高温下的粘性系数进行了比较;对后者在常温下的多组加、卸载和蠕变实验曲线进行了力学特征分析.

The creep experiments have been done on Lc4 aluminum alloy,TC11 titanium alloy,the carbon constructional quality steels（20 steel,35 steel） under high temperature,and on electro deposited nickel thin film under room temperature.The integral creep constitutive equation and differential stress-strain constitutive relationship can be established according to relevant rheological model named revised Burgers and the integral core of the creep has been achieved through the experiments.Comparing the calculation results conducted from the model with the experiment results,they were in good agreement.Moreover,the coefficient γ〈（F）〉 related with viscosity of visco-plastic materials were obtained through creep experiments＇ datum.The viscosity coefficients under high temperature of the former three kind of materials were compared;and the mechanical characteristics of the loading,unloading and creep caves under room temperature of the electro deposited nickel thin film were also analyzed.