快速凝固/粉末冶金制备高硅铝合金材料的组织与力学性能

Microstructures and mechanical properties of high-silicon aluminum alloy fabricated by rapid solidification/powder metallurgy

采用空气雾化水冷与真空包套热挤压工艺相结合的方法,制备了Al 30Si和Al 40Si过共晶高硅铝合金材料,采用扫描电镜与金相显微镜进行了显微组织分析,检测了其力学性能。研究表明:所制备的高硅铝合金粉末颗粒尺寸在2～10μm之间;挤压后的材料具有组织十分细小且均匀弥散分布的Si相;在370℃热挤压条件下,其抗拉强度高达239MPa,比相同成分的铸轧态试样提高了77%,随着挤压温度的升高以及Si含量的增加,硅相颗粒增大,抗拉强度下降。

Hypereutectic high-silicon aluminum alloy(Al-30Si and Al-40Si)was fabricated with a method in which air-atomization was followed by vacuum canning hot-extrusion process. Microstructure was analyzed by SEM and optical microscopy; tensile strength was examined and discussed. Experimental results show that, powder particle size is approximately 210 μm; silicon crystals are fine and uniform distributed by extrusion. The tensile strength reaches 239 MPa at 370 ℃ extrusion , increases 77% compared with as cast, while tensile strength decreases, Si crystal grows up with both the extrusion temperature and the Si content increasing.