Advances in Shot Peening of Silicon Nitride Ceramics

Author:  W. Pfeiffer and T. Frey
Source:  Conf Proc: ICSP-9 (pg 326-331)
Doc ID:  2005105
Year of Publication:  2005
Abstract:  
ABSTRACT Shot peening is a common procedure to improve the static and cyclic strength of metal components. It is based on a multiple localized plastic deformation of near-surface regions. Ceramics show at room temperature the typical brittle material behavior of failure before deformation. Thus, strengthening of ceramics due to deformation induced compressive residual stresses has been thought to be not possible. Recent investigations showed, however, that also in brittle materials like ceramics high compressive stresses can be introduced near the surface. This presentation compiles the status of the novel shot peening technique applied to silicon nitride ceramics. The results show that high compressive residual stresses in the GPa-range can be introduced in silicon nitride which may boost the static and cyclic load capacity of the near surface layer by a factor of up to 5. In addition, the fracture toughness of the near-surface region is dramatically improved.