On the correlation between solid-particle erosion and fracture parameters in SiC

Abstract

The fracture toughness,K _Ic, for a hot-pressed SiC and three types of reaction-bonded SiC has been measured using the Hertzian indentation technique with spherical indentors whose radii varied from 2.5 to 10 mm. Excellent agreement between the toughness measured by this technique and the publishedK _Ic value measured using double torsion is obtained for the hot-pressed SiC. The Vickers hardness,H, which was also measured, andK _Ic have been used to predict the solid-particle erosion rate, ΔW, given by ΔW ∞H _a K ^b_c where the values of the exponentsa andb depend on the details of the erosion model. The predicted rates are not in agreement with the measured rates. This discrepancy is probably due to the fact that the models are insensitive to microstructure.