Microstructure and tensile properties of cast Al-15%Mg2Si composite: Effects of phosphorous addition and heat treatment
Microstructure and tensile properties of cast Al-15%Mg2Si composite: Effects of phosphorous addition and heat treatment
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DOI：
10.1016/j.msea.2012.07.011
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发表时间：
2012-10-30
期刊：
影响因子：
6.4
通讯作者：
Norouzi, M. H.
中科院分区：
文献类型：
--
作者：
Nasiri, N.;Emamy, M.;Norouzi, M. H.
研究了固溶热处理和磷添加对原位Al-15%Mg2Si复合材料试样显微组织和拉伸性能的影响。 Al-15%Mg2Si 复合材料锭采用原位工艺制造，并在重熔复合材料中添加不同量的磷（0.1、0.3、0.5、0.7 和 1 wt% P）。然后，将试样在500℃固溶，保温4小时，然后淬火。光学显微镜（OM）和扫描电子显微镜（SEM）表明，磷的添加不仅使初生Mg2Si颗粒的形貌从树枝状改变为规则形状，而且还减小了Mg2Si颗粒的尺寸。固溶导致 Mg2Si 颗粒溶解并将其形态改变为圆形。拉伸试验结果表明，磷添加和固溶热处理均可提高极限拉伸强度 (UTS) 和伸长率 (El.%) 值。结果表明，固溶热处理后的 Al-Mg2Si 复合材料中添加 0.5 wt% P 可获得最佳拉伸性能。断口分析揭示了 MMC 断裂表面的细胞性质。添加磷后，由于微观结构的改变，应力集中的潜在位点和裂纹萌生区域减少，而细韧窝数量的增加使断裂性质从脆性转变为延性，并且还改善了拉伸性能。 (c) 2012 Elsevier B.V. 保留所有权利。
The effects of solution heat treatment and phosphorous addition on the microstructure and tensile properties of in situ Al-15%Mg2Si composite specimens have been investigated. The Al-15%Mg2Si composite ingot was made by in-situ process and different amounts of phosphorous (0.1, 0.3, 0.5, 0.7 and 1 wt% P) were added to the remelted composite. Then, the specimens were subjected to solutionizing at 500 degrees C for holding time of 4 h followed by quenching. Optical microscopy (OM) and scanning electron microscopy (SEM) indicated that phosphorous addition not only changes the morphology of primary Mg2Si particles from dendritic to a regular shape, but also it reduces Mg2Si particle size. Solutionizing led to the dissolution of the Mg2Si particles and changed their morphology to round shape. The results obtained from tensile testing revealed that both phosphorous addition and solution heat treatment improve ultimate tensile strength (UTS) and elongation (El.%) values. According to the results, the optimum tensile property was achieved by adding 0.5 wt% P to the Al-Mg2Si composite after solution heat treatment. Fractographic analysis revealed a cellular nature for the fracture surface of the MMC. As a result of P addition the potential sites for stress concentration and crack initiation areas were reduced due to microstructural modification, while increase in the number of fine dimples rendered the nature of fracture from brittle to ductile and also improved tensile properties. (c) 2012 Elsevier B.V. All rights reserved.