Experimental and numerical residual stress analysis of layer coated composites

Industrial requirements concerning the increased efficiency of modern machine components combined with low material and production cost targets result in the development of new composite materials and material combinations. Especially the application of functional coatings on light metals by thermal spraying can fulfil both requirements. The knowledge of the mechanical and functional properties of the coating is a key requirement for an optimized and repeatable manufacturing process and reproducible high quality composites. These coating properties as well as the lifetime and operation behaviour are mainly influenced by the residual stress situation. This paper describes a new approach to the simulation of the thermal spraying process by modelling a moving heat source in combination with the material transfer and deposition process. The calculated stresses and deformations are consistent with experimental residual stress measurements by means of the advanced hole drilling method. In addition the influence of the residual stresses on the mechanical coating properties is investigated. (C) 2000 Elsevier Science S.A. All rights reserved.