(1. 華南理工大學(xué) 材料科學(xué)與工程學(xué)院，廣州 510640；
2. 廣州金邦有色合金有限公司，廣州 510340)
摘 要: 以A356-1.3%Fe再生鋁合金為原材料，通過(guò)Mg-Si熔體直接反應(yīng)制備20%Mg2Si/A356-1.3%Fe鋁基復(fù)合材料，研究B和Cr對(duì)復(fù)合材料組織中初始Mg2Si和富Fe相變質(zhì)行為以及研究變質(zhì)處理對(duì)拉伸性能和耐磨性的影響。結(jié)果表明：B和Cr分別對(duì)復(fù)合材料中的初生Mg2Si相和β-Fe相具有較佳的變質(zhì)效果，B-Cr復(fù)合能夠?qū)崿F(xiàn)初生Mg2Si相和β-Fe相的同步變質(zhì)。針狀Fe相全部轉(zhuǎn)變成漢字狀或骨骼狀α-Fe相，長(zhǎng)徑比減小近90%，初生Mg2Si相由粗大的樹(shù)枝晶狀轉(zhuǎn)變成細(xì)小的顆粒狀，平均尺寸由70.2 μm減小到36.4 μm，約下降50%。與A356-1.3%Fe再生鋁相比，復(fù)合材料的耐磨性提高約3倍，而經(jīng)B-Cr變質(zhì)的復(fù)合材料其抗拉強(qiáng)度提高27%，斷裂應(yīng)變提高73%。
關(guān)鍵字: 再生鋁；復(fù)合材料；初生Mg2Si；富Fe相；變質(zhì)
（1. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China;
2. Guangzhou Jinbang Non-ferrous Alloy Limited Company, Guangzhou 510340, China）
Abstract:A356-1.3%Fe recycled aluminum alloy was chosen as raw material to prepare 20%Mg2Si/A356-1.3%Fe composites by direct melt reaction between Mg and Si. Modification behaviors of B and Cr elements on primary Mg2Si and Fe-rich phases in the composites and its influence on tensile properties and wear resistance were mainly investigated. The results show that the elements of B and Cr can effectively modify primary Mg2Si and Fe-rich phases, respectively. Simultaneous modification of primary Mg2Si and Fe-rich phases can be effectively achieved by the combination of B and Cr. All of the needle-like β-Fe phases are changed into α-Fe phase like Chinese-script characters or skeleton. The aspect ratio of Fe-rich phase is reduced by 90%. Morphologies of primary Mg2Si phase are changed from coarse dendrite to small granular. Its average size is reduced by about 50% from 70.2 μm to 36.4 μm. Compared with A356-1.3%Fe recycled aluminum, the wear resistance of the composites is improved by 3 times, and the tensile strength and elongation to failure of the composites modified by B and Cr are increased by 27% and 73%.
Key words: recycled aluminum alloy; composites; primary Mg2Si phase; Fe-rich phase; modification
