【摘要】 利用压痕裂纹扩展法获得ＴｉＣ，ＴｉＮ／Ｓｉ３Ｎ４复合材料的阻力曲线，采用指数经验公式拟合处理实验数据，探讨了公式中各参数的物理意义和影响因素。结果表明：指数经验公式拟合参数与材料的性能之间存在着密切联系。裂纹扩展路径的ＳＥＭ观察指出了一些较好的颗粒增韧方法更多还原

【Abstract】 Indentation crack growth method was used to obtain the R curves for TiC,TiN/Si 3N 4 ceramic composites.The empirical exponential equation K R =K ∞+(K ∞-K 0)· exp (-c/λ) is selected to fit the experimental data,and the physical meanings of parameters in the equation were discussed.Results of the experiments show that the empirical equation is well applicable for fitting the R curves and the obtained parameters are related to the material mechanical properties,with K ∞ and λ indicating the intrinsic crack toughness and the crack tolerance respectively.The SEM observation of path of the crack growth suggests some better particle toughening methods.更多还原