組織與力學性能
( 中南大學 材料科學與工程學院，長沙 410083)
摘 要: 采用空氣霧化水冷與真空包套熱擠壓工藝相結合的方法，制備了Al-30Si和Al-40Si過共晶高硅鋁合金材料，采用掃描電鏡與金相顯微鏡進行了顯微組織分析，檢測了其力學性能。研究表明：所制備的高硅鋁合金粉末顆粒尺寸在2～10 μm之間；擠壓后的材料具有組織十分細小且均勻彌散分布的Si相；在370℃熱擠壓條件下，其抗拉強度高達239 MPa，比相同成分的鑄軋態(tài)試樣提高了77%，隨著擠壓溫度的升高以及Si含量的增加，硅相顆粒增大，抗拉強度下降。
關鍵字: 快速凝固；真空包套；熱擠壓；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
