纳米SiC_P/AZ61镁基复合材料的时效行为研究

采用箱式热处理炉、显微硬度计、SEM电镜、能谱分析仪,对纳米SiCP/AZ61镁基复合材料的时效行为进行分析,结果表明,复合材料在时效初期,未观察到不连续析出相在晶界析出,却观察到Mg17Al12比较分散的从基体中析出;随着时效温度的提高,SiCP/AZ61复合材料或AZ61合金到达时效峰值所需的时间减少;在同一温度下,SiCP/AZ61复合材料要比基体合金的时效速度快,但时效的效果比基体合金差;且在同一温度下,SiCP/AZ61复合材料的硬度值要比基体合金的硬度值高,主要是因为采用了高能超声法,使纳米SiC颗粒均匀地分布在基体中。

Study on aging behavior of nano-SiCp reinforced AZ61 magnesium matrix composites

The aging behavior of nano-SiC particulates reinforced AZ61 magnesium matrix composites fabricated by Ultrasonic method was investigated with box-type heat treating furnace,Vickers hardness measurement,scanning electron microscopy (SEM) and energy spectrum analyzing apparatus.The results show that the discontinuous cellular precipitates at the grain boundaries are absent in the magnesium matrix,and the Mg17Al12 is precipitated preferentially at the matrix.The time to reach peak hardness for AZ61 alloy or SiCP/AZ61 composites is reduced with the increase of aging temperature;The composites exhibits accelerated aging but lower aging efficiency at the same temperature compared with the matrix alloy. And the micro-hardness of the composite is higher than that of the matrix alloy because of the added SiC particulates distributing homogeneously in the matrix.