Dghdgh

MATERIALS CHARACTERIZATION 75 (2013) 108–114

Available online at www.sciencedirect.com

www.elsevier.com/locate/matchar

Microstructure, strengthening mechanisms and hot deformation behavior of an oxide-dispersion strengthened
UFG Al6063 alloy
H. Asgharzadeha , H.S. Kimb , A. Simchic,⁎ a Department of Mechanical Engineering, University of Tabriz, P.O. Box 51666-16471, Tabriz, Iran
Department of Materials Science and Engineering, Pohang University of Science and Technology, P.O. Box 790-784, Pohang, South Korea c Department of Materials Science and Engineering and Institute for Nanoscience and Nanotechnology, Sharif University of Technology,
P.O. Box 11365-9466, Tehran, Iran b ARTICLE DATA

ABSTRACT

Article history:

An ultrafine-grained Al6063/Al2O3 (0.8 vol.%, 25 nm) nanocomposite was prepared via powder

Received 4 July 2012

metallurgy route through reactive mechanical alloying and hot powder extrusion. Scanning

Received in revised form

electron microcopy, transmission electron microscopy, and back scattered electron diffraction

12 September 2012

analysis showed that the grain structure of the nanocomposite is trimodal and composed of

Accepted 18 October 2012

nano-size grains (1 μm) with random orientations. Evaluation of the mechanical properties of the nanocomposite based on

Keywords:

the strengthening-mechanism models revealed that the yield strength of the ultrafine-grained

Ultrafine-grained materials

nanocomposite is mainly controlled by the high-angle grain boundaries rather than nanometric

Aluminum matrix nanocomposite

alumina particles. Hot deformation behavior of the material at different temperatures and

Microstructure

strain rates was studied by compression test and compared to coarse-grained Al6063 alloy. The

Hot deformation

activation energy of the hot deformation process for the nanocomposite was determined to be

Dynamic recrystallization

291 kJ mol− 1, which is