高压处理对Cu-50.84Cr-0.48Al合金热扩散系数和热膨胀性能的影响

Effects of High Pressure Treatment on Thermal Diffusion Coefficient and Thermal Expansion of Cu-50.84Cr-0.48Al Alloy

采用热常数测试仪和膨胀仪测试了经高压处理前后Cu-50.84Cr-0.48Al合金的热扩散系数和热膨胀系数,并借助金相显微镜、扫描电镜(SEM)和透射电镜(TEM)对经高压处理前后Cu-50.84Cr-0.48Al合金的组织进行观察。在此基础上,探讨了高压处理对Cu-50.84Cr-0.48Al合金热扩散系数和热膨胀系数的影响。结果表明:高压处理能增大Cu-50.84Cr-0.48Al合金的热扩散系数,当压力为1 GPa,该合金的热扩散系数为0.4188 cm2·s-1,较高压处理前的提高了10.65%,压力超过1 GPa时,合金的热扩散系数随压力的增大变化不明显。对热膨胀系数来说,当温度低于96℃时,1 GPa压力处理对合金的热膨胀系数影响不大,温度高于96℃时,1 GPa压力处理能增大合金的热膨胀系数。Cu-50.84Cr-0.48Al合金经高压处理后致密性的升高是导致该合金的热扩散系数及热膨胀系数增大的主要原因。

The thermal diffusion coefficient and thermal expansion coefficient of Cu-50.84Cr-0.48A1 alloy before and after high pres- sure treatment were measured by thermal constant tester and thermal expansion instrument, and the microstructure of the alloy before and after high pressure treatment were analyzed by metallurgical microscope, scanning electron microscope（SEM） and transmission e- lectron microscope（TEM）. Based on the experimental results, the effects of high pressure treatment on the thermal diffusion coefficient and thermal expansion coefficient of the alloy were investigated. The results showed that high pressure treatment could increase the thermal diffusion coefficient of Cu-50.84Cr-0.48A1 alloy, when the pressure was 1 GPa, the thermal diffusion coefficient of the alloy was 0.4188 cm2 ·s^ -1, which was 10.65% larger than that of the alloy before high pressure treatment, and when the pressure was above 1 GPa, the thermal diffusion coefficient had slight change with the pressure increasing. For thermal expansion coefficient, when the temperature was below 96 ℃, the 1 GPa pressure treatment had little effect on the thermal expansion coefficient of Cu-50.84Cr-0.48A1 alloy, and when the temperature was above 96 ℃, the 1 GPa pressure treatment could increase the thermal expansion coefficient. The increasing compactness of Cu-50.84Cr-0.48A1 alloy by high pressure treatment was the main reason for the increase of the thermal dif- fusion coefficient and the thermal expansion coefficient.