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http://dx.doi.org/10.7777/jkfs.2014.34.3.087

Thixo-extrusion of Semi Solid 7075 Aluminum Alloys and Mechanical Properties of The Extrudates  

Choi, Tae-Young (Dept. of Metallical and Materials Engineering, Gyeongsang National University)
Kim, Dae-Hwan (Dept. of Metallical and Materials Engineering, Gyeongsang National University)
Kim, Soo-Bae (Dept. of Metallical and Materials Engineering, Gyeongsang National University)
Shim, Sung-Young (Dept. of Metallical and Materials Engineering, Gyeongsang National University)
Lim, Su-Gun (Engineering Research Institute (Gyeongsang National University))
Publication Information
Journal of Korea Foundry Society / v.34, no.3, 2014 , pp. 87-93 More about this Journal
Abstract
Thixo-extrusion of semi-solid 7075 aluminum alloy and the mechanical properties of its extrudates were investigated. The semisolid alloy was prepared by a cooling slope cast. In other to perform thixo-extrusion, semi-solid 7075 aluminum alloy billets were reheated at the reheating conditions reported in a previous study. The maximum extrusion pressure in thixo-extrusion was 615MPa. This was lower than that of conventional hot extrusion ($P_{max}=940MPa$) at the same extrusion conditions due to the increased fluidity of the alloy billet in the semi-solid state. The values of Rockwell hardness (scale B) at the extrusion direction of the as thixoextruded bar were 48~53HRB and the difference in Rockwell hardness between the transverse direction and the extrusion direction was 5HRB or less. The results show that thxio-extrusion of semi-solid 7075 Al alloy improves the workability and anisotropic with the extrusion direction compared with hot extrusion of the conventional alloy.
Keywords
Al-Zn-Mg alloy; Semi-solid alloy; Thixo-Extrusion; Cooling plate;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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