工业纯钛TA2的室温压缩蠕变预测模型

Prediction Model for Room Temperature Compression Creep of Commercially Pure Titanium TA2

在室温下对工业纯钛TA2进行恒应力(200～550 MPa)压缩蠕变试验和恒应变速率(1×10-5,5×10-5,5×10-4 s-1)压缩试验,采用幂律方程(蠕变方程)描述了其压缩蠕变行为,利用修正的Arrhenius方程(压缩本构方程)描述了压缩流变行为;建立了压缩蠕变方程参数和压缩本构方程参数的关系式,利用蠕变临界应力修正后,得到基于压缩试验数据的室温压缩蠕变预测模型,并进行了试验验证。结果表明:工业纯钛TA2的室温压缩蠕变临界应力为252MPa;修正后的Arrhenius方程可以很好地表征工业纯钛TA2的室温压缩变形行为;采用室温压缩蠕变预测模型计算得到的蠕变曲线与试验曲线的相对误差均在10%以内,模型较准确。

Compression creep tests under constant stresses ( 200-550 MPa ) and compression tests atconstant strain rates (1×10^-5,5×10^-5,5×10^-4s^-1 ) were conducted on commercially pure titanium TA2at roomtemperature.The compression creep behaviour was described by power law equation(creepequation ) .Thecompression rheological behaviour was described by modified Arrhenius equation( compression constitutiveequation ) .The relation between parameters of comperssion creep equation and compression constitutive equationwas established and modified by creep critical stress.The prediction model for room temperature compression creepwas obtained on the basis of compression test data and verified by expriments.The results show that thecompression creep critical stress at room temperature of commercially pure titanium TA2was 252MPa.The roomtemperature compression defromation behaviour of commercially pure titanium TA2 were expressed well by themodified Arrhenius equation.The relative errors between the creep curves by the prediction model for roomtemperature compression creep and the tested curves were all below 10% ,indicating that the model was accurate.