Strong strain path dependence of strain localizations and fracture in magnesium AZ31 sheet

Journal of Magnesium and Alloys

Mert Efe¹  O. Berk Aytuna²  Kıvanç Alkan²  Baran Güler² 

[1] Corresponding author.;Department of Metallurgical and Materials Engineering, Middle East Technical University, Ankara 06800, Turkey;

关键词: Formability;    Twinning;    Biaxial;    DIC;    AZ31;   

DOI  :  

来源: DOAJ

【 摘 要 】

This study compares the deformation and fracture behavior of a basal-textured Mg AZ31 alloy sheet under uniaxial tension and biaxial stretching by using an in-plane biaxial test setup capable of observing and measuring the deformation at both meso (millimeter) and microstructure scales. Strain distributions at the mesoscale and accompanying fracture surfaces indicate a significant dependence on strain path. At the microscale, limited slip activity in biaxial case promotes contraction twins, where severe strain localizations (εmax/εmean ≈ 20) to the twins and their boundaries cause mainly transgranular fracture. This leads to a brittle, and a more pronounced shear-type fracture under biaxial stretching. In uniaxial case, considerable tensile twinning activity reorients the initial texture for slip activity. Strain localizations (εmax/εmean ≈ 2) to the grain interiors and boundaries initiate mainly intergranular fracture. Samples fail by displaying both brittle and ductile fracture structures, with smaller shear lips compared to the biaxial case.

【 授权许可】

Unknown