球磨工艺参数对Mg-1.5Zr合金阻尼性能的影响

Effect of ball-milling parameter on damping properties of Mg-1.5Zr alloy

采用机械合金化和粉末压制、烧结的方法制备Mg-1.5Zr合金,通过金相组织分析、力学性能测试和动态热机械技术研究球磨转速和球料质量比对该合金显微组织、力学性能和阻尼性能的影响。结果表明,当球磨转速从280 r/min增加到310 r/min时,合金的晶粒细小,合金的密度、显微硬度和抗弯强度均达到最大值,分别为1.743 g/cm3、46.73 HV和222.63 MPa,阻尼性能最好,耗能因子(tanφ)高达0.113。进一步提高球磨转速至350 r/min时,合金的组织粗化,显微硬度、抗弯强度、密度和阻尼性能均有所下降。增大球料质量比有利于细化晶粒,并提高Mg-1.5Zr阻尼合金的力学性能和密度。Mg-1.5Zr合金的阻尼峰温度随频率增大而升高,拟合结果表明驰豫时间满足Arrhenius关系,呈现弛豫型阻尼特征。

Mg-1.5Zr alloys were prepared by mechanical alloying and powder pressed sintering technology.The effects of ball-milling rotation speed and ball to powder ratio on microstructures and properties of Mg-1.5Zr alloys were researched by metallographic analysis,mechanical properties tests and dynamic mechanical analyzer（DMA） technology.The results show that as ball-milling rotation speed increases from 280 r/min to 310 r/min,the grains of the Mg-1.5Zr alloy are refined,and the mechanical properties,density and damping capacities reach the high values.However,when further increasing ball-milling rotation speed to 350 r/min,the grains become coarse,and the micro-hardness,bending strength,density and damping capacities are all decreased.With the increase of ball to powder ratio,the grains of Mg-1.5Zr alloys are more refined,and the mechanical properties and density of the alloys are increased.The temperature of the damping peak of Mg-1.5Zr alloys increases with frequencies,and the relaxation time meets the Arrhenius relationship,showing the characteristic of relaxation damping.