Session: AM9.1 - Materials for (strategic sectors) Aerospace and Defense applications

Paper Number: 189212

189212 - Theoretical Investigation of Laser Shock Peening on Fatigue Performance of Hard Anodized Aa 7075 Alloy 

The surface integrity and crack initiation susceptance due to fluctuating loads and environmental factors limit the life of aerospace structural materials such as high strength, relatively brittle aluminium AA 7075 alloy. Despite the excellent mechanical properties, the presence of surface brittleness and localised stress concentration compromise the fatigue performance of these materials. Use of sustainable surface processing techniques to improve the surface integrity and crack resistance at surface and near surface level, rather than in bulk material, may be a preferable approach. Surface processing techniques involving conventional coating methods such as hard anodizing, enhances strength and corrosion resistance of these materials by coating protective layers, however the fatigue life reduces due to brittle nature of coating layer. Other surface processing techniques involving induced compressive residual stresses to harden surface, improving hardness, wear resistance, as well as fatigue life, without adding or removing external material, preferable in cases of weight sensitive application. This proposed theoretical study examines the fatigue performance of AA 7075 alloy treated with laser shock peening technique, under various cyclic load conditions and comparing with conventional surface coating methods. The study validates the simulation results with uniaxial fatigue test (dog-bone test) for fatigue characterization of AA 7075 alloy. Further, this study proposes to investigate the usability of inducing residual stress as secondary process to surface coating.

Presenting Author: J. Saandip Dattaa National Institute of Technology Warangal

Presenting Author Biography: Currently pursuing Post Graduation at National Institute of Technology, Warangal.