Mechanisms of elastodynamic erosion of electron-beam thermal barrier coatings

Abstract

Abstract The elastodynamic response of a columnar thermal barrier coating to normal impact by a spherical particle is explored using an explicit finite element method. The transient stress state involves a tensile component at the edge of each column, and this may lead to erosion. The contact problem can be simplified to the impact of a single column by an inclined wedge. The peak tensile stress is determined as a function of geometry of column and level of friction between wedge and columns. The initiation of a crack from a pre-existing flaw within the column is explored. The implications of the various calculations are discussed for erosion of thermal barrier coatings.