Solid particle erosion behaviour of thermal sprayed ceramic, metallic and polymer coatings

Abstract

A study is made of the solid particle erosion behaviour of a set of thermal sprayed ceramic, metallic and polymer coatings as well as bulk alumina and stainless steel. The role of particle properties such as hardness and shape in slurry and airborne erosion is examined. The effect of varying the impingement angle of the airborne erodent stream on the erosion loss and rate of each coating is determined. Scanning electron microscopy (SEM) of the eroded surfaces is used to ascertain the erosion mechanisms. It is shown that hard, angular particles cause more severe damage than softer, more rounded ones. Coating properties such as hardness do not show correlation with erosion rates. Instead, the coating microstructure and defect population are seen to have a controlling influence on the erosion mechanisms.