压-压疲劳加载对2D-C/C复合材料导热性能的影响

对二维编织炭/炭复合材料(2D-C/C复合材料)进行压-压疲劳试验,疲劳加载条件分别为应力水平1000 N、2000 N和3000 N,循环周次为10~4、1×10~5、3×10~5次时,并测试其疲劳加载前后试样的导热性能,研究了压-压疲劳加载对其导热性能的影响.结果表明,压-压疲劳加载没有改变2D-C/C复合材料试样的热扩散系数随温度升高而减小以及比热容随温度升高而增大的基本规律,但是压-压疲劳加载使其热导率、热扩散系数随着应力水平和循环周次的增大而降低,而其比热容的变化较小.在压-压疲劳加载过程中,2D-C/C复合材料疲劳损伤的产生和积累导致其导热性能降低.

Effects of the Compressive Fatigue Loading on the Thermal Conductivity Behavior of 2D-C/C Composites

The compressive fatigue experiment of 2D-C/C composites was made under the stress level of 1000 N,2000 N and 3000 N,cycling times of 10~4,10~5 and 3×10~5,the thermal conductivity behavior is tested before and after the fatigue loading,and the effects of compressive fatigue loading conditions on the thermal conductivity behavior of the composites were investigated.The results show that compressive fatigue loading does not change the law about the thermal diffusivity coefficient and specific heat capacity improve with the increasing temperature.However,after the compressive fatigue loading,the thermal conductivity coefficient,thermal difFusivity coefficient of the samples reduce with the increasing of the stress level and cycling times,while the specific heat capacity change little.The decline of the thermal conductivity is related to the fatigue damages generated and accumulated during the compressive fatigue loading after analysis.