强织构AZ31镁合金板材深低温轧制过程中微观组织演变及力学性能控制研究

发布时间：2018-12-17 05:56

【摘要】：取初始织构为c轴与板面法向垂直的强织构AZ31镁合金板材为初始样品,经液氮温度深低温轧制多道次至不同变形量,研究所得轧制板材的显微组织与织构演变,及其对轧制力学性能的影响。利用SEM、EBSD和XRD表征分析了轧制板材的显微组织和织构,应用准静态单轴拉伸实验分别测试了深低温轧制板材沿轧向(RD)和横向(TD)的室温力学性能。研究表明,{1012}拉伸孪晶是深低温轧制强织构AZ31镁合金板材中的主导孪晶类型,其对轧制板材的微观组织和织构影响较为显著。轧制变形后,大量的拉伸孪晶晶界不但对晶粒起到了分割碎化作用,并且由于孪晶对取向的剧烈改变,使得板材在轧制变形后c轴平行于ND的织构组分加强。深冷轧制板材的强度有所提高,但是延伸率却急剧下降,沿着RD方向的强度要高于TD方向的强度。
[Abstract]:The microstructure and texture evolution of the rolled AZ31 magnesium alloy sheet were studied by taking the strong texture AZ31 magnesium alloy sheet with c axis and plate surface as the initial sample and rolling through several times to different deformation amount through liquid nitrogen temperature and low temperature. And its effect on rolling mechanical properties. The microstructure and texture of rolled sheet were characterized by SEM,EBSD and XRD. The mechanical properties of (RD) and (TD) along rolling direction were measured by quasi-static uniaxial tensile test. The results show that {1012} tensile twin is the dominant twinning type in AZ31 magnesium alloy sheet rolled in deep and low temperature, and the effect on microstructure and texture of rolled sheet is significant. After rolling, a large number of tensile twinning boundaries not only play a role in splitting and breaking the grains, but also because of the sharp change of the twinning orientation, the c axis parallel to the texture composition of ND is strengthened after rolling deformation. The strength of cryogenic rolled sheet was increased, but the elongation decreased sharply, and the strength along the direction of RD was higher than that in the direction of TD.
【作者单位】：北京科技大学新金属材料国家重点实验室;
【基金】：国家自然科学基金项目No.51401019 中国博士后科学基金项目No.2014M550612 中央高校基本科研业务费项目Nos.FRF-TP-14-048A1和FRF-TP-15-0055A2 北京市教委共建项目No.FRF-SD-13-005B~~
【分类号】：TG146.22;TG339

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