Increased fatigue strength of partially stabilised zirconia achieved by shot peening

Abstract

The effects of shot peening (SP) on the fatigue strength of partially stabilised zirconia were studied. Smooth specimens and specimens containing a surface pre-crack with depths in the range 35–110 μm were subjected to SP. The cyclic fatigue tests were performed using a three-point bending setup. SP introduced compressive residual stresses on the specimens and improved their fatigue strengths. The shot peened specimens with pre-crack depths ≤ 50 μm fractured outside the pre-crack area and exhibited considerably high fatigue limits, equivalent to those of the shot peened smooth specimens. Therefore, the pre-cracks with depths ≤ 50 μm could be rendered harmless by SP, which was confirmed by the theoretical estimations based on fracture mechanics.

Keywords:

• Partially stabilised zirconia
• Shot peening
• Fatigue strength
• Residual stress
• Fracture mechanics

ORCiD

K. Takahashi http://orcid.org/0000-0001-5971-0582

H. Koike http://orcid.org/0000-0002-1307-7045