Effect Of Rolling And350℃×3h-annealing On The Microstructures, Mechanical Properties And Damping Capacity Of Mg-0.6%Zr-1.0%Cd Alloy

The casting ingot of Mg-0.6%Zr-1.0%Cd was investigated in this study. Unidirectional and cross rolling under the condition of high temperature and large deformation was employed to obtain two different rolling sheets. The respective half of the rolling sheets processed an annealing, so that sheets for different tempers were produced. Mechanical properties and damping capacities along the sheet’s rolling direction (0°), transverse direction (90°) and the22.5°,45°,67.5°direction to the rolling direction in the rolling plane were measured. Using optical microscopy, transmission electronic microscopy, scanning electronic microscopy, electronic tensile machine and DMA-Q800dynamic thermal analyzer and other techniques, the microstructures, mechanical properties and damping capacities of the sheets were contrastively analyzed; the textures of the sheets were measured using the technology of electron backscatter diffraction(EBSD); the relation between crystal orientation and anisotropic mechanical properties as well as anisotropic damping capacities were discussed. The results showed that:Dynamic recrystallization of the rolled plates take place obviously in the rolling processes. The Mg-0.6%Zr-1.0%Cd alloy forms lath twins, sub-grain structure and fine equiaxed structure. Fracture morphology gives a brittle fracture. After the annealing treatment of350°C×2hours, both sheets’grains show quiaxed structure and the organization machining marks have disappeared. The grain size of the cross-rolling sheet is smaller and more uniform than unidirectional rolling sheet. The dislocation density within the grains has been significantly reduced, while dislocation stacks are basically eliminated. Fracture surfaces of the annealed sheets show ductile fracture characteristics.Yield strength of the cross-rolled sheet is higher than that of unidirectional rolled sheet, tensile strength and damping performance are of no significant difference. Both plates exhibit anisotropy of mechanical properties:The strengths increase from0°to90°. Yield strength of the two plates is reduced and elongation is promoted. Tensile strength of unidirectional rolled sheet decreases significantly, while it increases in the direction of0°,22.5°and45°direction in cross-rolling sheet.The rolling samples show low damping performance but with a annealing, they exhibit damping capacities two times higher than that for rolling temper. The samples with lower damping performance show better mechanical properties, after better mechanical properties. EBSD test results show that both annealed sheets exhibit a strong a{0001} basal texture. Inverse pole figure shows that the distribution of the crystal orientation varies among different directions of the annealed sheets. The texture results may contribute to the anisotropy of Mechanical and Damping properties for the sheets.