A methodology development for the study of near surface stress gradients

A modification of the geometry used in the sin2 ψ technique of X-ray diffraction is described. A modified equation for residual stress determination, including geometric adapted Fij, is presented. This method allows near surface stress gradients determination and is called pseudo-grazing incidence method. The limits of the new technique were first tested on different powder materials with X-ray radiation produced by conventional tubes and by a synchrotron radiation source. The technique was finally applied for the determination of a residual stress profile in a polished molybdenum surface before and after the deposition of a PVD chromium film.