EROSION OF GLASS BY ALUMINA PARTICLES - TRANSITIONS AND EXPONENTS

The erosion of glass as a function of the velocity of alumina particle s of 30 mu m average size was studied. It was found that the use of th e rotating double-disk method to determine particle velocity can lead to systematic deviations. Correcting for this effect, the results indi cate that the erosion can be well described using indentation fracture mechanics. The exponent of the velocity-dependence of the removal rat e was found to be in good agreement with the value of 7/3 which is pre dicted by quasi-static indentation theory. Two transitions have been o bserved: at low velocities the removal process changes from ductile to brittle, while at high velocities fragmentation of the alumina partic les sets in. The corresponding impact loads can also be obtained from indentation theory and are in line with the observed effects.