高温组织与力学性能
(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 研究了Mg-9Gd-4Y-0.6Zr合金挤压T5态在250~400 ℃之间的高温组织与力学性能。 结果表明： 该合金具有非常优异的高温力学性能， 其力学性能明显优于WE54； 该合金在250、 300、 350和400 ℃时的抗拉伸强度分别为348、 262、 150和62 MPa；该合金在400 ℃拉伸时还具有粗晶超塑性，晶界上有再结晶的细晶， 晶内有大量孪晶同时共存。
关键字: Mg-Gd-Y-Zr合金； 耐热镁合金； 高温力学性能； T5态；粗晶超塑性
elevated temperatures
（ School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The microstructures and mechanical properties of the extruded Mg-9Gd-4Y-0.6Zr-T5 at temperatures between 250 ℃ and 400 ℃ were investigated. The results show that this alloy has outstanding mechanical properties and high heat-resistance, and its mechanical properties are markedly better than those of WE54. The tensile strength of this alloy at 250, 300, 350 and 400 ℃ are 348, 262, 150 and 62 MPa, respectively. In tensile test at 400 ℃, the sample shows a coarse-grained superplasticity, which is not reported, and a great deal of recrystallized grains are found on grain boundaries and a lot of twins occur within the grains.
Key words: Mg-Gd-Y-Zr alloy; heat-resistant magnesium alloy; high temperature mechanical properties; T5 temper; coarse-grained superplasticity
