Study of Surface Residual Stress Variation according to the Process Variables of Ultrasonic Nanocrystal Surface Modification

Compressive residual stresses generated on the surface by ultrasonic nanocrystal surface modification vary according to the process variables. In this study, surface compressive residual stresses were analyzed according to process variables using finite element analyses. Finite element analysis methodology was introduced. The surface compressive residual stresses according to the static load, amplitude, feed rate, and line interval were calculated through 3D finite element analyses. As the static load and amplitude increased, the magnitude and depth of the surface compressive residual stress increased. Furthermore, the feed rate and line interval were analyzed in terms of the overlapping ratio. As the feed rate and line interval increased, the overlapping ratio decreased and the magnitude of the surface compressive residual stress in each direction decreased.