Orientation Dependence on Fatigue Fracture Behavior in Uniaxial Fatigue Tests of Pure Mg Single Crystals

Abstract

Three Mg single crystalline round-bar specimens with different crystal orientations were subjected to uniaxial tension-compression fatigue tests, and crystal orientation dependence on fatigue fracture behavior was investigated. Loading directions of AD, BC and EF specimens were [11 20], [1 100] and [0001] respectively. Results show that, at stress amplitude (• a ) greater than or equal to 60 MPa, fatigue life of BC specimen was longest, while that of EF specimen was shortest. Under stress amplitude of 20 MPa, crystal orientation dependence on fatigue lives was not confirmed. Our study suggests that fatigue life in Mg single crystals show a high degree of dependence on crystal orientation and stress.

Roles of Slip and Twinning on Indentation Formations in Magnesium Alloy Single Crystals

“…However, as HCP metals are known to show greater crystal orientation dependence on deformation behavior compared to cubic metals, deformation mechanisms have been studied using HCP single crystals. Tensile tests, 1,2) compression tests, 3) pure shear tests, 4) and fatigue tests 5,6) of HCP single crystals have been conducted to investigate such deformation mechanisms. These studies have discovered activated slip systems, twin systems, and critical resolved shear stress (CRSS).…”