Effect of Shot Peen Forming with Large Balls on Fatigue Resistance of 2024-T351 Aluminum Alloy

摘要

Shot peen forming different from shot peening is a metal forming process widely used in aeronautical industry. Different types of tension-tension fatigue specimens after peen forming were tested. The results show that the fatigue life of specimens peen formed with large balls except edges is 35.4% higher than that of unpeened specimens, while the life of the specimens with whole surface peen formed is 23.2% lower than that of the unpeened specimens. In addition, shot peening specimens which have been peen formed as a surface strengthening way can significantly improve the fatigue resistance. Moreover, when the specimen is peen formed except edges, the position of crack source is from the indentation region to subsurface.