On the use of microscale abrasion test for determining the particle abrasivity

Abstract

Particle abrasivity is an important concept for helping to select materials for pumps and for disc cutters in underground excavation, and specific ASTM standards are available for making these selections. However, for manufacturing processes in which abrasive action is their core, the particle size range is approximately a fewmicrometers. The evaluation of particle abrasivity using the microscale abrasion test matches this range of particles for this purpose, but relatively few investigations using this kind of method have been conducted. The aim of this investigation is to use the microscale abrasion test to evaluate the particle abrasivity, avoiding changes on the ball surface and on the particle size distribution. Samples of quenched AISI D2 tool steel were used for tests. The wear mode was dependent on the testing time. Alumina (Al2O3) particles presented a lower abrasiveness when compared to boron carbide (B4C) ones, confirmed by the higher wear coefficient found in the latter after reaching the steady-state regime. This behavior was evidenced by the number of active particles in the contact, which showed that there were a larger number of B4C particles than Al2O3 during the contact at all sliding distances. The particle abrasivity is discussed in terms of significant characteristics of slurries: particle shape, particle size distribution, hardness-to-elastic modulus ratio, zeta potential, and density. As the controlling of those characteristics seems to be very important, particle abrasivity is a concept that needs to be improved besides the test system used for that purpose.