组织与力学性能
( 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 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2～10 μm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239 MPa，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。
关键字: 快速凝固；真空包套；热挤压；Al-Si合金
rapid solidification/powder metallurgy
（School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: 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 2-10 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.
Key words: rapid solidification; vacuum canning; hot extrusion; Al-Si alloy
