Reduction of Residual Stress in Aluminum Alloys using Ultrasonic Cleaning Peening

Abstract

One of the surface modification treatments to improve fatigue life is shot peening, but it requires time and cost, and it is challenging to apply to narrow areas. Another method under study is cavitation peening, but it also takes time for the treatment. In this research, the ultrasonic cleaning peening (UCP) is considered as a method for reducing the residual stress. UCP is relatively simple and can be applied to various material shapes using an ultrasonic cleaner. In this presentation, the residual stress and hardness before and after UCP in specimens subjected to tensile residual stress by a general-purpose processing machine was discussed. The results obtained are as follows. (1) Tensile residual stress caused by cutting or grinding process tends to change to compressive residual stress due to the UCP. (2) There is a relationship between UCP and cleaning effect; the higher the cleaning effect, the higher the compressive residual stress. (3) The Vickers hardness with an indentation load of 10 N shows no change in surface hardness due to the UCP.