EFFECT OF ERODENT HARDNESS ON EROSION OF BRITTLE MATERIALS

Data in the literature suggest that the relative hardness values of the erodent particles and the target sample may play a significant role in the erosion behavior of ceramics. When the ratio of the target hardness to the hardness of the erodent particle approaches unity, there is a sharp transition in erosion rates. Relatively soft erodents lead to less erosion. Based on scanning electron microscopy observations, it is suggested that softer erodents can fragment and crush on impact. In steady state, it appears that the lateral crack-based erosion mechanisms still operate, but for softer erodents damage accumulation is necessary to build up the requisite stresses to produce lateral cracks. Changes in the erosion velocity exponent can also occur. They have been attributed to particle blunting effects and/or R-curve behavior.