塑性变形条件下的接触热导率测试

Testing thermal contact conductance under plastic deformation

利用激光热导仪和自制的夹具,通过测试接触副的总热扩散率和求解一维瞬态热传导方程,得到接触热导率与总热扩散率的函数关系,实现了在塑性变形条件下的接触热导测量。当压力增加到铝试样屈服强度的5.89倍时,硬度较小的铝试件变形率达到50%,接触热导率达到7.2 W/(cm2.K)。实验结果表明,接触热导率与压力之间呈幂指数关系变化,在试件发生屈服变形后,随压力增大,接触热导率的变化趋于平缓。通过对实验数据进行回归分析,得到了在接触副材料发生塑性变形条件下的接触热导率模型。

The testing of thermal contact conductance under plastic deformation was realized by making use of laser diffusivity apparatus and the clamp made by ourselves, the relationship between thermal contact conductance and the total thermal diffusivity was obtained by testing the total thermal diffusivity of the contacted bodies and then solving one-dimensional instantaneous thermal conduction equation. The deformation ratio of aluminum reaches 50%, and the thermal contact conductance is up to 7.2 W/（cm^2· K） when the pressure is increased to 5.89 times of aluminum＇s yielding strength. The testing results indicate that thermal contact conductance varies with the pressure by exponential. The thermal contact conductance model under plastic deformation was obtained by analyzing the experimental data.