An investigation of impingement erosion using single particles

Abstract

The impingement erosion process is studied by investigating the effect of impact of relatively large single particles on an aluminum surface. The material removal action is shown to have the same physical characteristics as multiple impingement erosion of solid surfaces. Based on observations of the crater formed by these single particles, on both annealed and previously work-hardened surfaces, it is proposed that material is removed by a displacing action that results in fracture of removed material at sufficient strain. This process is comparable to some single point cutting experiments. In considering a mathematical model of this process, a particle penetration equation based on indentation hardness theory is used. It is shown that this model, which does not consider strain hardening or inertia of the impacted surface, is valid for the relatively low impact velocities considered here. The principal result of this analysis is that a velocity exponent of 3 is predicted for both the particle velocity and diameter exponents. This result matches more closely with experimental evidence than previous theories.