钙元素对Mg-9Al-0.8Zn合金抗拉强度和蠕变性能的影响

Effect of Ca Element on Tensile Strength and Creep Resistance of Mg-9Al-0.8Zn Alloys

研究了Mg-9Al-0.8Zn合金中添加少量钙元素后的力学性能。结果表明:该合金的屈服强度随钙添加量的增加而增加。含有0.15%Ca的合金能获得最大的抗拉强度。在150~200℃时,随着钙元素添加量的增加,蠕变性能也显著增加。添加0.15%Ca的合金蠕变率(200℃,50 MPa)比基体合金低一个数量级。钙的添加能细化显微组织和增强β析出相的热稳定性,并且蠕变抗力也有所改善。

The mechanical properties of Mg-9Al-0.8Zn alloy after adding small amounts of Ca to Mg-9Al-0.8ZnZn（AZ91） alloy were studied.The results show that the yield strength of the alloys increases with the increase of Ca addition and the maximum strength can be obtained from the alloy containing 0.15%Ca. The creep resistance at the temperatures between 150- 200 ℃ significantly increases with Ca addition increasing.The creep rate （at 200 ℃, 50 MPa） of the alloy with 0.15%Ca addition is one order of magnitude lower than that of the base alloy （AZ91）. The addition of Ca can refine the microstructure and enhance the thermal stability of β precipitate phase, and then the creep resistance improves.