Effect of Rolling Temperature on Microstructure and Properties of Mg-1Al Alloy

The annealed Mg-1Al alloy (mass fraction/%) with thickness of 12.5 mm was rolled at different temperatures (280, 320, 360, 400 ℃) for two passes with reduction rates of 20% and 80%, respectively. The effect of rolling temperature of the microstructure, tensile, and damping properties of test alloy was investigated by field emission scanning electron microscope, dynamic thermomechanical analyzer and X-ray diffractometer. The results show that with the increase of rolling temperature, the dynamic recrystallization of test alloy was more complete.When the rolling temperature was 360 ℃, the dynamic recrystallization was basically complete,and twins began to appear in the alloy. With the increase of rolling temperature, the intensity of the (0002) basal texture initially increased and then decreased, reaching the maximum value of 13.801 at 320 ℃; the yield strength and tensile strength decreased, and the elongation after fracture increased first and then decreased. When the rolling temperature was 360 ℃, the tensile properties were the best. Under relatively high strain amplitudes,the room temperature damping increased with the increase of strain amplitude or rolling temperature. After rolling at different temperatures, the test alloy all exhibited damping peaks of P₁ and P₂ at 100–150 ℃ and 270–320 ℃, respectively. The peak value of P₂ peak decreased with the increase of rolling temperature, indicating the decline of high temperature damping properties of the alloy.