制备工艺对铝基复合材料增强体颗粒分布均匀性的影响

采用高能球磨法混料和低温快速热挤压相结合的粉末冶金工艺制备了SiCp/6066Al复合材料,研究了制备工艺对增强体颗粒分布均匀性的影响.结果表明:高能球磨法混料是显著改善增强体颗粒形貌、细化增强体颗粒粒度,在基体更小的微区域中实现增强体颗粒数量分布均匀性的最有效混料方法;低温快速热挤压利用基体的较低塑性和强大物理变形量使增强体颗粒进一步细化,得到的细小等轴颗粒更易随着基体的塑性流动而呈弥散均匀分布,进一步改善或消除微区域内增强体颗粒的偏聚或尽可能降低偏聚的程度.两种方法相结合是实现增强体颗粒微观分布均匀性的最有效方法.

Effect of Fabricating Parameters on Spatial Distribution of Reinforcements in Aluminum Matrix Composites

SiCp/6066Al composites were fabricated by the method of high energy ball milling and quick hot extrusion at low temperature. The effect of this method on the SiC particles distribution was investigated. The results indicate that high energy ball milling is the most effective powder mixing method, which can remarkably improve the shape of reinforcements, reduce their size and lead to the dispersed homogeneous distribution of reinforcements in quantity at smaller micro-areas in the matrix. By using the low ductility and great distortion of matrix, quick hot extrusion at low temperature can ulteriorly reduce the size of reinforcements and produce fine axial symmetrical reinforcements which can more easily distribute homogeneously with the matrixes flow. It can also improve or eliminate the gather of reinforcements at micro-areas in the matrix or mostly depress the gather degree of reinforcements. High energy ball milling combined with quick hot extrusion at low temperature is the most effective method which leads to the uniform distribution of reinforcements in the matrix at micro-level.