High Cycle Fatigue Property of Extruded Non-Combustible Mg Alloy AMCa602

Abstract

Rotating bending tests were performed at room temperature on the non-combustible magnesium alloy AMCa602, which was produced by adding 2% calcium (Ca) to the AM60 magnesium alloy. The fatigue strength at 107 cycles was approximately 100 MPa. The fatigue property was strongly dependent on the inclusion size. In order to identify the type of the inclusion at the crack initiation site, elemental analyses were conducted by an electron probe microanalyzer (EPMA). The inclusion at the crack initiation site was AlN, which may have originated from impurities mixed in during casting. The relation between da/dN and ΔK was analyzed by the crack propagation behavior, and the fatigue life was evaluated by using the Paris law. As a result, it was clarified that most of the fatigue life was spent on crack initiation and micro crack propagation.