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http://dx.doi.org/10.5228/KSPP.2007.16.5.391

Characteristics on the Hot Extrusion of Semi-Solid Al-Zn-Mg Alloy  

Cho, Kuk-Rae (한국기계연구원부설 재료연구소/소재성형센터)
Yeom, Jong-Taek (한국기계연구원부설 재료연구소/소재성형센터)
Shim, Sung-Yong (경상대학교 재료공학부, 항공기 부품기술연구센터)
Lim, Su-Gun (경상대학교 재료공학부, 항공기 부품기술연구센터)
Park, Nho-Kwang (한국기계연구원부설 재료연구소/소재성형센터)
Kim, Jeoung-Han (한국기계연구원부설 재료연구소)
Publication Information
Transactions of Materials Processing / v.16, no.5, 2007 , pp. 391-395 More about this Journal
Abstract
Semi-solid Al-Zn-Mg alloys were produced by using a cooling plate method in order to investigate the extrudability. Al melt was poured on cooling plate which was adjusted at $60^{\circ}$ with respect to the horizontal plane, and the melt was cooled by water circulation underneath. Obtained Semi-solid feedstock has globular microstructure but also contains considerable amount of gas pore. Due to the pore, tensile elongation of the semi-solid feedstock was very low and it doesn't show yield point phenomenon. Isothermal hot extrusion was carried out using at $400^{\circ}C$ with a ram speed of 1mm/sec and an extrusion ratio of 25:1. The extruded bar show noticeably improved tensile ductility and strength because pore volume fraction decreased from 5% to 0.8% after extrusion. Mechanical properties of the semi-solid extruded bar were compared with that of commercial casting alloy.
Keywords
Semi-Solid Alloy; Hot Extrusion; Al-Zn-Mg; Mechanical Properties;
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