Feasibility of Local Stress Relaxation by Laser Annealing and X-ray Measurement

Most manufacturing processes generate residual stresses inside the materials and components. Stress relief heat treatments can be used to reduce the magnitude of the residual stresses: by uniformly heating a structure to a sufficiently high temperature, and then uniformly cooling it, residual stresses can be relaxed. This process generally requires the insertion of the entire component in a large furnace, for a fairly long period of time. In this paper, the possibility of using a high power laser source to locally relieve residual stresses is studied; this has the advantage of calibrating and confining the relief process just to the laser affected area. An experimental set-up was tested on an aluminium specimen, and the preliminary results are reported in this paper.