Abstract
The present study describes effects of micro shot peening including shot blasting on an improvement of mechanical properties of silicon nitride and alumina ceramics. Different shapes, such as grid or bead, and material of the impact media were used and were collided to the target ceramics surface with pressurized air using developed peening apparatus. The hardness and toughness of the surface was evaluated from micro indentation apparatus at various indent loads. Results showed that the fracture toughness and the hardness were different depending on the impact media material. A relationship between the hardness and the fracture toughness and the effect of impact media material on the surface modification were discussed
