过共晶Al-16%Si合金梯度功能材料的组织与性能

Structure and Properties of Hypereutectic Al-16%Si Alloy Functionally Gradient Materials

采用离心技术成功地制备了过共晶Al 1 6%Si合金梯度功能材料。采用金相及扫描电子显微镜、HV 5型小负荷维氏硬度计及销盘式ML 1 0 0型磨粒磨损试验机研究了该梯度功能材料的组织、硬度及耐磨性的分布规律。结果表明 ,由于Si的密度比Al液的密度稍低 ,在离心力场中初晶硅向试样内侧移动。Al 1 6%Si合金梯度功能材料的组织分布为 :最内层初晶硅含量最多、尺寸也最大 ,由内向外 ,初晶硅的体积分数及尺寸均逐渐减小 ,且呈梯度变化。在外层一定厚度内 ,完全不含初晶硅 ;硬度分布为内层硬度较高 ,由内向外硬度逐渐减小 ,呈梯度分布 ;

Hypereutectic Al 16%Si alloy functionally gradient materials (FGM) are made by centrifugal casting method.The gradient distribution law of structure,hardness and wear resistance of the FGM are researched by means of optical microscope and SEM,HV 5 model light load Vickers,and ML 100 model pin disk abrasive wear testing machine.The results show that the primary crystal Si particles segregated to the inside of specimens in centrifugal field because the density of Si is smaller than that of Al alloy melt.The content and size of the primary crystal Si particles decrease gradually until they disappear from inside to outside of the specimens,and change in gradient.The hardness and wear resistance of Al 16%Si alloy FGM decrease gradually from inside to outside of the specimens,and change in gradient.