Contact mechanics of graded coatings

摘要

The main interest of this study is in the fracture initiation in graded coatings under sliding contact loading. The structural component under consideration is a metallic substrate bonded to a metal/ceramic coating with continuously varying thermo-mechanical properties. The coating is 100% ceramic at the free surface and 100% metal at the interface. It is assumed that the thickness variation of the shear modulus of the coating is exponential and the Poisson's ratio is constant. The loading is provided by a sliding rigid stamp subjected to constant normal and tangential forces and the underlying elasticity problem is two-dimensional. On the contact area, it is also assumed that the conditions of Coulomb friction prevail. The objective of the study is to obtain a series of analytical benchmark solutions for examining the influence of such factors as material inhomogeneity constants, the coefficient of friction and various length parameters on the critical stresses that may have a bearing on the fatigue and fracture of the coating. (C) 2004 Elsevier Ltd. All rights reserved.