TiC-ZrC-Co-Ni金属陶瓷的抗热震性能

Thermal Shock Resistance of TiC-ZrC-Co-Ni Cermets

真空烧结制备了TiC-ZrC-Co-Ni系金属陶瓷。利用压痕-急冷法研究了金属陶瓷的抗热震性能,并通过材料的物理性能及力学性能对热震裂纹的稳定性参数Rst进行了理论计算。实验结果表明,由于热应力作用,热震温度越高,材料的裂纹扩展越快,并且,在相同条件下,四组试样中ZrC含量为10%时,裂纹扩展速度最慢,表明其抗热震性能最好。理论计算结果也显示,ZrC含量为10%的试样的热震裂纹稳定性参数Rst最高。金属陶瓷材料的抗热震性能可以通过理论计算进行预测。

TiC-ZrC-Co-Ni series cermets were prepared by vacuum sintering. The thermal shock resistance of cermets was tested by indentation-quench method, and also, the thermal stress crack stability parameter, R,, was calculated using the physical and mechanical properties of these cermets. The experimental results show that the higher thermal shock temperature is, the faster crack propagates because of the effect of thermal stress. Moreover, under the same condition, the speed of crack propagation is the slowest in the sample with 10%ZrC, which means its thermal shock resistance is the best. The result of theoretical calculation also shows that the thermal stress crack stability parameter, Rst, is the highest with 10%ZrC. The thermal shock resistance of cermets can be estimated by theoretical calculation.