Study of Residual Stress in the Vicinity of Interface Corner of Sprayed Coatings.

This paper deals with the singularity of residual stress arising at the interface corner of sprayed substrates and the effects of specimen size, mechanical and physical properties on residual stress distributions using the theory of elasticity and a boundary element method (BEM).The residual stress distribution is not only defined by one singular term, then it is difficult to use a stress intensity factor as the parameter to define the strength of sprayed substrate.The residual stress distribution of test specimen satisfying following conditions are the same as that of sprayed substrate in a working field : The test specimen is composed of the substrate with the thickness being 4 times, and the length and the width being 8 times as large as a thickness of sprayed coating.The preheat temperature TB of substrate in order to make a residual stress zero is given by the temperature of sprayed coating and the ratio of linear thermal expansions of coating and substrate materials.