Thermal shock behaviors of SiC ceramic with artificial defects were studied. Artificial surface cracks were simulated by Vickers and Knoop indentations, and artificial inner cracks were obtained using novel method of introducing plastic fibers. The residual flexural strength and microstructure were analyzed. The flexural strength of artificial defect free SiC ceramic maintains minimum 87% of the original strength after thermal shock ΔT no more than 400 ℃, and the residual strength of those with artificial crack, no matter surface type or inner type, can still be improved by the joint effect of thermal treatment, thermal shock and the stress relaxation by artificial crack if ΔT no more than 400 ℃. It is believed that inner and surface artificial defects ease the crack propagation during the thermal shock process.

研究了具有人工缺陷的SiC陶瓷的热冲击行为。用维氏和努氏压痕模拟了人造的表面裂纹，并使用引入塑料纤维的新方法获得了人造的内部裂纹。分析了残余弯曲强度和显微组织。无人工缺陷的SiC陶瓷的抗弯强度在热冲击ΔT不超过400℃时至少保持原始强度的87％，并且无论是表面类型还是内部类型，带有人工裂纹的残余强度都可以通过以下方法得到改善： ΔT不超过400℃时，热处理，热冲击和人工裂纹引起的应力松弛共同作用。据信，内部和表面的人工缺陷在热冲击过程中减轻了裂纹的传播。