Induction of Through-Thickness Compressive Residual Stresses and Application to the Mitigation of the Effect of Surface Defects on the Fatigue Life of Thin Metal Plates by LSP

Abstract

Laser Shock Processing (LSP) is developed as a technique allowing the effective induction of residual stresses fields in metallic materials allowing a high degree of surface material protection against fatigue crack propagation, abrasive wear, chemical corrosion and other failure conditions, what makes the technique specially suitable and competitive with presently use techniques for the treatment of heavy duty components in the aeronautical, nuclear and automotive industries. In particular, the treatment of thin plates for, i.e., the aeronautical industry, is still a topic not fully addressed by the current industrial approaches. The desired induction of through-thickness compressive RSs fields is generally difficult to achieve due to the local + global deformations induced by highenergy- per-pulse processing systems.The authors have directly envisaged this problem by means of their coupled predictive + experimental methodology and have obtained successful results. In a combined way, the highly beneficial effect of LSP treatments has been demonstrated in the extension of life of thin Al2024-T351 test specimens with induced surface notches.