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Semi-solid metal casting (SSM) is a near net shape variant of die casting.〔(【引用サイトリンク】title=Welcome to MyNADCA! )〕 The process is used with non-ferrous metals, such as aluminium, copper,〔Young, p. 1.〕 and magnesium. The process combines the advantages of casting and forging. The process is named after the fluid property thixotropy, which is the phenomenon that allows this process to work. Simply, thixotropic fluids shear when the material flows, but thicken when standing.〔 The potential for this type of process was first recognized in the early 1970s.〔.〕 There are four different processes: ''thixocasting'', ''rheocasting'', ''thixomolding'', and ''SIMA''. SSM is done at a temperature that puts the metal between its liquidus and solidus temperature. Ideally, the metal should be 30 to 65% solid. The metal must have a low viscosity to be usable, and to reach this low viscosity the material needs a globular primary surrounded by the liquid phase.〔 The temperature range possible depends on the material and for aluminum alloys is 5–10 °C, but for narrow melting range copper alloys can be only several tenths of a degree. Semi-solid casting is typically used for high-end castings. For aluminum alloys typical parts include engine suspension mounts, air manifold sensor harness, engine blocks and oil pump filter housing.〔P. Kapranos, Proc. 10th Inter. Conf. Semi-Solid Processing of Alloys and Composites, Aachen, Germany & Liege, Belgium, 2008〕 ==Processes== There are a number of different techniques to produce semi-solid castings. For aluminum alloys the more common processes are ''thixocasting'' and ''rheocasting''. With magnesium alloys, the most common process is ''molding''.〔S. LeBeau & R Decker, "Microstructural Design of Thixomolded Magnesium Alloys", Proc. 5th Inter. Conf. Semi-Solid Processing of Alloys and Composites, Golden, Colordao, 1998〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Semi-solid metal casting」の詳細全文を読む スポンサード リンク
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