Tan Yun, Li Wei, Hu Weiwei, Shi Xiaofang, Tian Liang
College of Material and Metallurgy, Guizhou University, Guiyang 550025, China.
Guizhou Province Technology Innovation Service Center, Guiyang 550004, China.
Materials (Basel). 2019 May 12;12(9):1554. doi: 10.3390/ma12091554.
Deformation of an as-rolled rare earth Mg-2Y-0.6Nd-0.6Zr alloy, at different temperatures, was carried out along the BC (90° anticlockwise rotation of the samples after each ECAP pass) route by equal channel angular pressing (ECAP). The effects of the deformation temperature and the predeformation on the microstructure of the magnesium alloy were determined by the microstructure examination. The slip systems and texture change of the Mg-2Y-0.6Nd-0.6Zr alloy were investigated by X-ray diffraction (XRD) and electron backscattered diffraction (EBSD), after equal channel angular deformation. The results showed that after seven passes of rolling, the grain size in the Mg-2Y-0.6Nd-0.6Zr alloy was refined to approximately 22 µm and the slip occurred mainly by a cylindrical slip and a pyramidal slip. After one pass of ECAP at 340 °C, the internal average grain size was significantly reduced to 11 µm, the cylindrical diffraction intensity clearly weakened, and the pyramidal diffraction intensity increased. EBSD pole figure analysis revealed that the base texture of the rolled Mg-2Y-0.6Nd-0.6Zr alloy weakened from 24.31 to 11.34 after ECAP. The mechanical properties indicated that the tensile strength and elongation of the rolled Mg-2Y-0.6Nd-0.6Zr alloy reached maximum values, when the deformation temperature was 340 °C.
对铸态稀土镁合金Mg-2Y-0.6Nd-0.6Zr在不同温度下，通过等径角挤压（ECAP）沿BC路线（每次等径角挤压道次后样品逆时针旋转90°）进行变形。通过微观组织观察确定了变形温度和预变形对镁合金微观组织的影响。通过X射线衍射（XRD）和电子背散射衍射（EBSD）对等径角变形后的Mg-2Y-0.6Nd-0.6Zr合金的滑移系和织构变化进行了研究。结果表明，经过七道次轧制后，Mg-2Y-0.6Nd-0.6Zr合金的晶粒尺寸细化至约22μm，滑移主要通过柱面滑移和锥面滑移发生。在340°C下进行一道次等径角挤压后，内部平均晶粒尺寸显著减小至11μm，柱面衍射强度明显减弱，锥面衍射强度增加。EBSD极图分析表明，等径角挤压后，轧制态Mg-2Y-0.6Nd-0.6Zr合金的基面织构从24.31减弱至11.34。力学性能表明，当变形温度为340°C时，轧制态Mg-2Y-0.6Nd-0.6Zr合金的抗拉强度和伸长率达到最大值。
