Particle Impact Conditions in Vibratory Sand-Erosion Facilities

A statistical method has been developed for the purpose of determining the particle impact conditions in vibratory sand-erosion testing facilities, which use a magnetostriction vibratory unit for vibrating the specimen in a fluidized-bed or fixed-bed sand of particles. The point of the method is to use the frequency distribution of scale parameter, as well as shape parameter, of the craters which are formed on the specimen surface by the impact of sharply-sieved sand particles. An apparatus for free-falling particle-in-vacuum was also used to obtain the standard frequency distribution of crater parameters under known impact conditions. The particle impact velocity in the vibratory facility was then confirmed by comparing the frequency distribution of the crater scale parameter on the specimen with that of the standard conditions. The crater shape parameter was used to confirm the impact angle. The impact frequency was determined by simply counting the number of craters formed on the specimen surface. As a result, the following impact conditions were confirmed. Fluidized-bed: impact velocity of 1.7-2.4m/s, impact frequency of 106l/cm2·s, impact angle of 90°, independent of specimen geometory. Fixedbed: impact velocity of 1.4m/s, impact frequency of 106l/cm2·s, any impact angle controllable by specimen geometory.