Investigations in Abrasive Water Jet Erosion Based on Wear Particle Analysis

Abstract

In the study, gray cast iron specimens are cut by abrasive water jets with pressures between p = 140 MPa and p = 345 MPa. Wear particles collected during cutting are analyzed based on average grain size and grain size distribution. The average diameter of the removed wear particles was found to be between D = 60 μm and D = 70 μm and drops with rising pump pressure. A semi-empirical model is developed to describe this relation. The grain distribution of the wear particles can be characterized by a Rosin-Rammler-Sperling (RRSB)-distribution. The surface area of the removed wear particle samples increases with an increase in the pump pressure. The progress drops at higher pressure levels indicating accelerated efficiency losses if the pump pressure exceeds a certain value. An efficiency parameter, Φ, is defined which relates the jet kinetic energy to the creation of the wear particles, and a method for its estimation is developed. It was found that the efficiency parameter exhibits a maximum value at a pressure level of about three times the material threshold pressure. The average efficiency parameter is estimated to φ = 0.02.