A crusher for single particle testing

Abstract

For the investigation of particle failure in abrasive processes a single particle crusher has been developed. Basically the apparatus consists of two approaching diamond anvils between which a particle is positioned. Both the force and displacement can be either measured or controlled during an experiment. The force is determined by the current through the voice coil with a resolution of 0.5 mN. The vertical displacement of the lower anvil is measured by three inductive displacement transducers, each with a resolution of 0.1 μm. Single abrasive particles in the size range 10–500 μm can be used. The crushing process can be monitored through the upper anvil by a long distance microscope and recorded video. Preliminary experiments show that three different failure mechanisms can be distinguished: chipping, breaking, and fragmentation. By far the most dominant failure mechanism is chipping. The data of the crushing experiments are represented in a Weibull plot. The generally low value for the Weibull modulus indicates a large variability in strengths of the abrasive particles.