Multiaxial Cyclic Response of Low Temperature Closed-Die Forged AZ31B Mg Alloy
The present study investigates the multiaxial fatigue behavior of extruded AZ31B Mg alloy forged at 250 °C. Fatigue samples were tested under axial–shear loading at phase angles of 0°, 45° and 90°. The microstructural analysis identified dynamic recrystallization, which resulted in a degree of grain refinement of the forged microstructure in addition to a modification of the original extrusion texture. Quasi-static testing showed that the forged material retained the high yield strength of the extrusion condition with a substantial increase in failure strain. Under multiaxial loading, cyclic axial strain significantly affected the shear hysteresis behavior while the effect of cyclic shear strain on the axial hysteresis was less pronounced. Despite a notable change in shear hysteresis shape, fatigue life was only slightly affected by the changes in phase angle.
KeywordsMagnesium alloy Forging Microstructure Texture Multiaxial fatigue
The financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC) through the Automotive Partnership Canada (APC) program under APCPJ 459269–13 grant with contributions from Multimatic Technical Centre, Ford Motor Company, and Centerline Windsor are acknowledged. The authors would also like to thank J. McKinley and L. Blaga of CanmetMATERIALS for assistance with the forging trials.
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