粉末冶金法AlN颗粒增强镁铝基复合材料的阻尼性能

Damping Capacity of AlN Particles Reinforced Magnesium-Alumnium Matrix Composites by Powder Metallurgy

镁合金具有低密度与高的阻尼性能,是一种理想的减震与噪音控制材料.文中选择AlN颗粒为增强体,研究了不同含量的AlN颗粒对Mg-Al基体合金微观组织的影响,并深入讨论了不同含量的AlN颗粒对复合材料的阻尼性能的影响规律.采用粉末冶金法制备AlNp/Mg-Al基复合材料,通过动态机械分析仪研究了基体合金与复合材料的阻尼性能随温度、频率与增强相含量的变化规律.实验结果表明:当颗粒添加相质量分数为3%时,复合材料的阻尼性能最好.室温下,复合材料的阻尼性能均优于基体合金,但是随着增强相含量与频率的增加,复合材料的阻尼性能逐渐降低.基体合金与复合材料的内耗-温度曲线在100～150℃的温度范围内呈现与位错有关的内耗峰,复合材料在200～250℃的温度范围内呈现与界面滑移有关的内耗峰.

Magnesium alloys with low density and high damping capacity are promising materials to address the problems such as vibration and noise control.In this paper,the effect of different mass fraction AlN particle on the microstructure of magnesium-aluminum matrix alloys was investigated,and the effect of different mass fraction AlN particle on the damping capacity of magnesium-aluminum matrix composites was also discussed.The AlN particle reinforced magnesium-aluminum matrix composites were prepared by powder metallurgy.The effect of temperature,frequency and reinforcement content on damping capacity of the matrix alloy and composites were investigated by dynamic mechanical thermal analysis.The results show that the best damping capacity of composites are reached with the 3% mass fraction of AlN reinforcement addition.The damping capacity of the AlN particle reinforced magnesium matrix composites is better than that of the alloy at room temperature.Meanwhile,the damping capacity of composites decreases with the increasing of reinforcement and frequency.The internal friction peaks related to dislocation appear at 100~150 ℃.There is also an internal friction peak of magnesium matrix composite reinforced by AlN particles at the temperature of 200~250 ℃,which is related to interface sliding.