LASER SURFACE COATING FATIGUE INTERACTION OF 2017A-T3 (ALUMINUM ALLOY)

Abstract

The interaction of fatigue and laser peening with different surface coatings was studied for 2017A-T3 aluminum alloy under stress ratio R= -1 and room temperature (RT) .This interaction is a major issue in the practice life assessment of aircrafts. The current work examined the effect of laser surface with different coatings i.e. ALP (Air laser peening), BPL (Black paint laser peening) and WLP (Water laser peening) on cumulative fatigue. The experimental results observed that the fatigue strength was improved by 18% and 35% under BPL and WLP respectively. A new non-liner damage model was derived to predict the cumulative fatigue lives . This model showed safe and satisfactory predictions for unpeend and peened specimens for all cases of surface coatings. While Miner theory indicated not always suitable for life prediction of cumulative fatigue loading .