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http://dx.doi.org/10.7777/jkfs.2017.37.2.38

A Study on the Compressive Properties of Thixo-Extruded 7075 Aluminum Alloy  

Kim, Dae-Hwan (ReCAPT, Gyeongsang National Univ.)
Jung, Hyun-Ju (Intelligent machine & Material Part Center, GNTP)
Lim, Su-Gun (ReCAPT, Gyeongsang National Univ.)
Publication Information
Journal of Korea Foundry Society / v.37, no.2, 2017 , pp. 38-44 More about this Journal
Abstract
Given that the conventional extrusion of high-strength Al alloys such as 7075 aluminum alloys is difficult due to their very low extrudability as compared to that of 6061 aluminum alloys, thixo-extrusion can be used to obtain a high-strength material easily at a lower extrusion pressure as compared to conventional extrusion. In this study, hot- and thixo-extruded 7075 aluminum alloys are prepared by a vertical forward extrusion process and their microstructures, hardness levels, and compressive properties are investigated. Hot-extruded alloy bars are assessed to obtain a microstructure elongated in the extrusion direction, whereas with thixo-extruded alloy bars, it was possible to obtain a microstructure having fine and equiaxed grains by dynamic recrystallization. The resulting isotropy and improved formability at the hot deformation temperature of the thixo-extruded alloy were attributed to the fine and equiaxed grains formed by the thixo-extrusion process.
Keywords
Thixo-extrusion; Semi-solid casting; Compressive property; Al 7075 alloy;
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