Manufacturing Slurry and Rheocasting of Hypereutectic Al-Si-Cu-Mg Alloy
Manufacturing Slurry and Rheocasting of Hypereutectic Al-Si-Cu-Mg Alloy
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DOI：
10.4028/www.scientific.net/msf.706-709.420
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发表时间：
2012-01
期刊：
影响因子：
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通讯作者：
Y. Uetani;N. Mori;Masayoshi Dohi;K. Matsuda;S. Ikeno
中科院分区：
文献类型：
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作者：
Y. Uetani;N. Mori;Masayoshi Dohi;K. Matsuda;S. Ikeno
用一种新开发的简单方法快速稳定地制备了过共晶Al-14.8%Si-4.5%Cu-1.1%Mg合金(质量分数)，该合金具有细小的固体颗粒和细小弥散的初生硅颗粒，低过热度熔体通过旋转的规则八角形转子和外接冷铁块之间的间隙。通过考察中间包出口熔体温度、气隙间距和转子转速对半固态浆料凝固组织的影响，找出了目标半固态浆料的最佳制备条件。制备速度快、重现性好的浆料中固体颗粒平均尺寸为45μm，初生硅颗粒平均尺寸为20μm。随后，利用高压铸造机将得到的半固态浆料流变浇注到圆柱形的型腔中。结果表明，流变铸件的硬度介于重力铸造和热挤压之间，但其良好的时效硬化性能略高于重力铸造。
Both rapid and stable semi-solid slurry preparation of hypereutectic Al-14.8%Si-4.5%Cu-1.1%Mg alloy (in mass%) with fine solid granules as well as finely dispersed primary silicon particles was tried using a simple method newly developed, where the low-superheat melt passes through a gap between a rotating regular octagonal rotor and a circumscribed chill block. By examining effects of melt temperature running out from tundish, gap distance and rotational speed of rotor on solidification structure of the semi-solid slurry manufactured, the optimum making condition of the targeted semi-solid slurry was found out. Mean sizes of solid granules and primary silicon particles within the slurry, which had been made quickly with the good reproducibility, were 45μm and 20μm, respectively. Subsequently the obtained semi-solid slurries were rheocast into a cylindrical shape cavity by the use of a high pressure casting machine. It has been shown that the rheocast samples have peak hardness value between the gravity casting and the hot-extrusion, but a good age-hardenability somewhat higher than that of gravity casting.