International Journal of Chemistry and Material Science Vol. 1(7), pp. 182-188, July, 2013 ISSN 2327-5553 ©2013 Academe Research Journals

Full Length Research Paper

Backward extrusion of 7075 Al alloy in the semisolid state

Hossein Mohammadi* and Mostafa Ketabchi

Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.

*Corresponding author. E-mail: h.mohammadi63@gmail.com. Tel: +98 935 40 60 432.

Accepted 2 April, 2013

Abstract

In this study, 7075 Al alloy which has low extrudability has been thixoformed by backward extrusion process. The stress induced and melts activation (SIMA) route was used to obtain the required semi-solid feedstocks for thixoforming. Microstructure evolutions during partial remelting were studied at different temperatures. Results showed that a fine and globular microstructure can be obtained by the SIMA route. Back-extrusion of 7075 Al alloy was performed in the semi-solid state at 580°C for 10 min holding time. Microstructure and mechanical properties of thixoformed components before and after the T6 heat treatment were examined at room temperature. The weak tensile properties and low hardness values in the as-thixoformed parts were improved by subsequent heat treatment.

Key words: Semi-solid processing, 7075 Al alloy, microstructure, mechanical property.