A Study on Surface Durability of Induction-Hardened Sintered Powder Metal Rollers : Influences of Powder Type, Sign of Specific Sliding and Relative Radius of Curvature

Abstract

In order to obtain fundamental data about tooth-surface durability and the tooth-surface failure mode of induction-hardened sintered powder metal gears, rollers made of two kinds of powders with diameters of 30 and 60 mm were fatigue-tested with pairs of same-diameters rollers under a sliding-rolling contact condition. The surface failure mode in this experiment was spalling due to subsurface cracking. The depth of the spalling crack agreed with the depth of the maximum amplitude of the ratio of orthogonal shear stress to Vickers hardness. The surface durabilities of the rollers increased as the relative radius of curvature decreased, and they were hardly influenced by the powder type and the sign of specific sliding.