Kinematic Modeling and Deformation Mechanics in Shot Peening of Functional Ceramics

The applications of ceramics are limited by their brittle nature and low reliability. Recent studies show that compressive residual stress can be introduced in ceramics by shot peening, which can improve the contact strength and fatigue of ceramics. However, the formation mechanism of residuals stress has not been investigated yet. In this study, a pressure dependent plasticity model has been incorporated into a FE model of shot peening to shed light on the residual stress formation mechanism. Since shot velocity is the key process parameter to dominate the impact energy which determines the deformation state of surface material and the resultant residual stress, a new kinematic model of shots has also been developed by incorporating air drag and travel distance inside and outside the peening nozzle. The results have shown that the kinematic model can be used to predict shot velocity. The FE model provided an insightful understanding of the residual stress formation mechanisms.