Three-point bending behavior of a ZEK100 Mg alloy at room temperature

Three-point bending and tensile tests were performed on rare earth containing ZEK100 at room temperature and various displacement rates (1.0, 5.0, 10.0, 20.0 and 50.0 mm/min). The bend was either parallel to the rolling direction (RD specimens) or the transverse direction (TD specimens). The TD specimens presented higher bendability than the RD specimens. For the TD specimens, fracture did not occur at low displacement rates of 1.0, 5.0 and 10.0 mm/min, but occurred at 20.0 and 50.0 mm/min. Fracture occurred in the RD specimens at all the displacement rates. Cracks were observed in both the compression zone and the tension zone. Tensile tests in the RD and the TD show that the ductility in the TD is about three times as much as in the RD, leading to the better bendability in the RD specimens. The initial texture was examined by X-ray diffraction (XRD) and the results show that the (0001) basal texture was weakened and spread along the TD due to the addition of the rare earth elements. In-situ electron backscatter diffraction (EBSD) analysis was performed when the specimen was being bent, and the results show that {101¯2}〈101¯1¯〉 twinning was activated in both the compression zone and the tension zone, different from highly textured AZ31 sheets. Our results indicate that the ZEK100 Mg alloy still presents anisotropy in the tensile properties and in the bending behavior, despite the weakened basal texture.