Cyclic Hardening Behavior of Extruded AZ31B Magnesium Alloy during Low Cycle Fatigue Process

Abstract

The strain-controlled fatigue tests on extruded AZ31B magnesium alloy were conducted under the uniaxial loading with strain ratio Rε=-∞, frequency of 0.1 Hz and strain amplitude of 2% at room temperature. The cyclic hardening behavior was investigated. It was found that, during the low cycle fatigue (LCF) process, as the number of cycles increases, the stress amplitude increases corresponding to the decrease of the plastic strain amplitude. The development of dislocation density can be described as the function of the number of fatigue cycles, and the behavior can be explained well based on the dislocation density development model.