Study of superficial stress gradients by computer simulation and x-ray diffraction experiment

Abstract

Study of stress gradients is one of the important problems of the X-ray tensometry, especially, in the case of analysis of residual stress state arising after different modern treatments like material modifications by ion beam technologies or surface treatments by laser. These problems related directly with incompleteness of theoretical and experimental measurement techniques with using of X-ray diffraction for study of stress gradients and they are connected with nonlinear character of dependency of diffraction angle θφ,ψ versus sin2ψ and with broadening of diffraction line caused by surface stress gradient. Computer simulation gives possibility to resolve the problem of determination of stress state characterized by strong gradient. The objective of presented paper is to develop a methodology of determination of stress gradient parameters. The methodology is based on computer simulation of diffraction line and permits to make corrections of stress measurements made by diffraction sin2ψ-method.