AZ31镁合金的织构对其力学性能的影响

Texture and its effect on mechanical properties of AZ31 magnesium alloy

利用电子背散射衍射(EBSD)取向成像技术,分析AZ31镁合金热挤压棒材和轧制薄板的织构特点;对具有不同初始织构的镁合金棒材和薄板进行力学性能分析,并从织构角度分析棒材的拉压不对称性和薄板的力学各向异性。结果表明:挤压镁合金棒材具有主要以(0001)基面平行于挤压方向的基面纤维织构,存在严重的拉压不对称性,其原因在于压缩时的主要变形方式为{1012}<1011>孪生;热轧镁合金薄板具有主要以(0001)基面平行于轧面的强板织构,具有显著的力学性能各向异性,其原因在于拉伸时不同方向的基面滑移Schmid因子不同。

The textures of both as-extruded rod and as-rolled sheet of AZ31 magnesium alloys were investigated by the electron back scattering diffraction （EBSD） technique.The influences of the initial textures on the mechanical properties in two different magnesium alloy behaviors,extruded rod and rolled sheet,were examined.The tensile-compressive asymmetry of extruded rod and mechanical anisotropy of rolled sheet were studied in the sight of texture.The EBSD results show that the major texture of as-extruded AZ31 rod is the fiber texture with （0001） basal plane parallel to the extrusion direction （ED）,while the major texture of as-rolled AZ31 sheet is the basal texture with （0001） basal plane parallel to the rolling surface.The mechanical property tests show that the activity of {1 012} 10 11 twinning during compression exerts significant effect on the tensile-compressive yield stress and elongation rate in an asymmetrical way.The different Schmid factors of basal slip systems in different directions lead to the in-plane anisotropy during tension.