热处理对挤压态AZ61合金力学性能和阻尼性能的影响

采用拉伸实验、硬度及电阻率测试、动态机械热分析、显微组织观察等方法研究了退火及时效对挤压态AZ61合金力学性能及阻尼性能的影响。结果表明:未经均匀化处理的AZ61合金热挤压后再经过退火(573K×1h),抗拉强度几乎不变;固溶处理(693K×1h)使合金的应变无关阻尼降低,但使应变相关阻尼提高。固溶处理后的时效(453K×24h)由于有少量第二相析出,明显提高合金的屈强比,且因增加了合金基体中强钉扎点的数量使阻尼性能较固溶处理后的稍有降低。该合金室温阻尼可用G-L位错钉扎模型解释。

Influence of Heat Treatment on Mechanical and Damping Properties of As-extruded AZ61 Magnesium Alloy

The mechanical and damping capacities of as-extruded AZ61 alloy were studied by tensile test,hardness measurement and dynamic mechanical analyzer. And the quantitative change of solution atoms was studied by electrical resistivity measurement. The experimental results show the annealing at 573K for 1h after extrusion don't decrease the tensile strength but the exposure to 693K for 1h decreases apparently,and annealing decreases Q-1o while increases Q-1h(?).The aging after solution treatment increases the yield/tensile strength and slightly decreases the damping capacity. The main damping mechanism of the alloy can be explained by G-L dislocation pinning theory.