PRELIMINARY ANALYSIS FOR A NEW APPROACH TO RELIEVE RESIDUAL STRESSES BY LASER HEATING

Residual stresses can be relaxed by supplying a sufficiently high amount of thermal [1, 2, 3] and/or mechanical energy. Several works, based on this principle, were carried out in the last years. Studies were realized on the prolonging fatigue life of a damaged steel by using the annealing treatment in a protective environment atmosphere [4], the effects of annealing prior to material dealloying on the mechanical properties [5] and in cold-rolled stainless steel [6] were also investigated; annealing treatments by a laser or a furnace were compared [2]. The purpose of this research was the measurement of materials’ residual stress relief and so a diode laser was used. This study aims to develop this innovative process of relief residual stresses, applying the annealing technique by using a high power laser source on an aluminum sample. X-ray diffraction was used to investigate residual stresses and the effect of annealing. This novel approach for relieving residual stresses has the advantage of being nondestructive and can be easily applied to in situ tests.