Improvement of fatigue strength of aluminum alloy by laser peening

Abstract

The effects of laser peening on the fatigue strength of A2024-T3 were investigated. Plane bending fatigue tests were conducted using test specimens treated with laser peening (LP) and shot peening (SP). In addition, surface roughness and residual stress distribution were measured and fracture surface was observed to evaluate the experimental results. As a result, it became clear that the fatigue strength was improved by any peening method. Also, the fatigue strength improvement rate for LP treated specimens were higher than that for SP treated specimens. These results indicated that the depth and magnitude of compressive residual stress are important for improvement of fatigue strength.