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

• 作者: Baran Guler Kivanc Alkan Mert Efe O.Berk Aytuna
• 来源期刊: 镁合金学报(英文)
• 学科: 工学
• 关键词: FORMABILITY TWINNING BIAXIAL DIC AZ31
• 年，卷（期）: mhjxbyw,（2）
• 页码范围: 472-479
• 页数: 8页
• 分类号: TG6

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≈220)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.