Effect of Icosahedral Phase on Crystallographic Texture and Mechanical Anisotropy of Mg-4％Li Based Alloys

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2017,（5）
• 页码范围: 475-480
• 页数: 6页
• 语种: 英文

摘要

Through investigating and comparing the microstructure and mechanical properties of the as-extruded Mg alloys Mg-4％Li and Mg-4％Li-6％Zn-1.2％Y (in wt％),it demonstrates that although the formation of I-phase (Mg3Zn6Y,icosahedral structure) could weaken the crystallographic texture and improve the mechanical strength,the mechanical anisotropy in terms of strength remains in Mg-4％Li-6％Zn-1.2％Y alloy.Failure analysis indicates that for the Mg-4％Li alloy,the fracture surfaces of the tensile samples tested along transverse direction (TD) contain a large number of plastic dimples,whereas the fracture surface exhibits quasi-cleavage characteristic when tensile samples were tested along extrusion direction (ED).For the Mg-4％Li-6％Zn-1.2％Y alloy,typical ductile fracture surfaces can be observed in both "TD" and "ED" samples.Moreover,due to the zonal distribution of broken I-phase particles,the fracture surface of "TD" samples is characterized by the typical "woody fracture".