高溫組織與力學性能
(中南大學 材料科學與工程學院，長沙 410083)
摘 要: 研究了Mg-9Gd-4Y-0.6Zr合金擠壓T5態(tài)在250~400 ℃之間的高溫組織與力學性能。 結(jié)果表明： 該合金具有非常優(yōu)異的高溫力學性能， 其力學性能明顯優(yōu)于WE54； 該合金在250、 300、 350和400 ℃時的抗拉伸強度分別為348、 262、 150和62 MPa；該合金在400 ℃拉伸時還具有粗晶超塑性，晶界上有再結(jié)晶的細晶， 晶內(nèi)有大量孿晶同時共存。
關鍵字: Mg-Gd-Y-Zr合金； 耐熱鎂合金； 高溫力學性能； T5態(tài)；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
