Deposition-induced residual stresses in plasma-sprayed coatings

Coupled heat transfer and elastic-plastic finite element analyses were conducted to study thermal stress generation and development during deposition of a nickel-cobalt (NiCoCrAlY) alloy on an aluminum disc (AA1100) substrate. A general purpose commercial finite element method (FEM) software ANSYS was used for the simulation of the temperature as well as stress and strain histories during the deposition process. A FEM special software feature called the element birth and death was used. The stress built-up during spraying was experimentally obtained by means of deflection measurement. A close agreement between the numerically predicted deflected shapes of the specimen and the experimental results indicated that the stress-strain distributions from the numerical elastic-plastic model could be applied with reasonable accuracy. (C) 2004 Elsevier B.V. All rights reserved.