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 s triking the surface, and in order to measure an erosion rate of a mate rial in which each particle strikes the surface independently of all o ther particles, as is generally assumed, experiments should be carried out at low particle fluxes. However, the flux used in testing is ofte n chosen arbitrarily with little rational basis for the choice. The me chanisms have been studied by which the erosive conditions depend on p article flux in a gas-blast erosion rig. The occurrence of particle-pa rticle interactions in the region between the nozzle and target, mainl y between incoming and rebounding particles, depends strongly on the f lux. A novel method has been used to determine the extent of particle- particle interaction, and to determine the flux below which the effect s of particle-particle interactions are insignificant. The method faci litates the generation of accurate and meaningful erosion data, within the shortest practicable time.