Solid Particle Erosion of Brittle Materials (Part4)

Abstract

Erosive wear by solid particle impingement was tested for 13 kinds of commercial Al2O3 ceramics. The erosion rate of Al2O3 ceramics is inversely proportional to the specific gravity, Al2O3 content and Vickers hardness of the target ceramics. The erosion rates of high density Al2O3 ceramics composed of more than 99wt% of Al2O3 are 3.9-4.5×10-3cm3/cm3, the same order as those of gas pressure sintered and hot pressed Si3N4. The erosion rate (V) of Al2O3 ceramics is related to its hardness (H) and fracture toughness (KIC) by the equation V=0.56H-1.2KIC-0.94, derived from the multiple regression analysis. Indices for H and KIC in the equation are different from those for hot pressed Si3N4, -0.27 for H and=7.1 for KIC. These differences are caused by the differences in erosion mechanism.