A METHOD FOR OPTIMIZING THE PARTICLE-FLUX IN EROSION TESTING WITH A GAS-BLAST APPARATUS

The erosive wear rate of a material depends on the flux of particles striking the surface, and in order to measure an erosion rate of a material in which each particle strikes the surface independently of all other particles, as is generally assumed, experiments should be carried out at low particle fluxes. However, the flux used in testing is often chosen arbitrarily with little rational basis for the choice. The mechanisms have been studied by which the erosive conditions depend on particle flux in a gas-blast erosion rig. The occurrence of particle-particle interactions in the region between the nozzle and target, mainly between incoming and rebounding particles, depends strongly on the flux. A novel method has been used to determine the extent of particle-particle interaction, and to determine the flux below which the effects of particle-particle interactions are insignificant. The method facilitates the generation of accurate and meaningful erosion data, within the shortest practicable time.