抄録
Rolling contact fatigue tests were carried out with two cylindrical specimens of sintered alloy. Damage of the specimen was detected by using acceleration sensor before occurrence of final failure. In order to study the behavior of damage process in contact fatigue behavior of sintered alloy, surface and cross section of the specimens were observed after the contact fatigue test. Damage on the specimen surface such as pitting mode of failure was not significantly observed. Contact fatigue damage was observed as subsurface crack initiation and propagation. Subsurface crack growth behavior was evaluated by an interrupted test. Crack length increased with increasing number of cycles. Crack initiation and propagation in the subsurface of specimen induced a spalling mode of fracture. Stress distribution of subsurface was estimated by FEM (Finite Element Method) analysis. The location of the maximum shear stress by FEM analysis coincided with the depth of crack initiation point observed in experiments. The position of the maximum shear stress approached to the specimen surface with increase in the tangential force at the contact surface. Subsurface crack growth behavior was dominated by shear stress amplitude.
