Tensile properties of hot rolled Mg_(97)Zn_1Y_2 alloy sheets at elevated temperatures

摘要

The elevated temperature tensile properties of Mg97Zn1Y2 magnesium alloy sheets, hot rolled at 390, 420 and 450 ℃ respectively, were tested in a temperature range from room temperature to 250 ℃ with a strain rate of 1.0×10-3 s-1. The results show that the variations in yield strength for Mg97Zn1Y2 magnesium alloy sheets hot rolled at 390 ℃ and 420 ℃ with temperature resemble each other due to their similar morphology of the chain-shaped strengthening phase. The yield strength maintains at a high level of 283 MPa before 200 ℃ and decreases significantly at 250 ℃. Despite of the fine lamellar structure of Mg97Zn1Y2 magnesium alloy sheet hot rolled at 450 ℃, its yield strength decreases linearly owing to occurrence of the coarse grain, and drops to 239 MPa at 250 ℃. The elongation for all hot rolled Mg97Zn1Y2 magnesium alloy sheets increases slightly with increasing testing temperature.