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

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 shap e in slurry and airborne erosion is examined. The effect of varying the imp ingement angle of the airborne erodent stream on the erosion loss and rate of each coating is determined. Scanning electron microscopy (SEM) of the er oded 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 ero sion rates. Instead, the coating microstructure and defect population are s een to have a controlling influence on the erosion mechanisms. (C) 1998 Els evier Science S.A. All rights reserved.