Abstract
The effect of the shot-peening on rolling contact fatigue of Si_3N_4 was investigated. Additionally we tried to clarify damage mechanism of rolling contact fatigue. By shot-peening, high compressive residual stress -8500MPa can be introduced near the surface. The residual stress can improve apparent fracture toughness K_<IC> and Vickers hardness HV of Si_3N_4 by approximately 73% and 8%, respectively. As a result, bending strength of pre-cracked specimen was improved 27〜46% by shot-peening. The delamination damage was inhibited by shot-peening, and as a result rolling contact fatigue of the Si_3N_4 was improved. These results are achieved by the compressive residual stress which is introduced by shot-peening. These results indicate that shot-peening is effective method to make use of ceramics as a rolling contact member.
