《Flow properties of commercial purity aluminum processed》.pdf

Materials Science and Engineering A 487 (2008) 264–270 Flow properties of commercial purity aluminum processed by equal channel angular pressing A. Sivaraman, Uday Chakkingal ∗ Materials Forming Laboratory, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600 036, India Received 9 August 2007; received in revised form 4 October 2007; accepted 8 October 2007 Abstract In this study the flow properties after equal channel angular pressing (ECAP) were investigated using commercial purity aluminum. Commercial purity aluminum samples were subjected to ECAP for up to four passes with a die angle of 90◦ using two different processing routes. Compression testing was used to determine the subsequent flow behavior. Two types of compression test specimens; one parallel to the axis of ECAP and the other at 45◦ to the axis of ECAP were machined from specimens subjected to different passes as well as different processing routes. Anisotropy in flow stress was observed for the ECAP processed specimens. Strain path change parameter was used to quantify the strain path change for this study. From the results higher flow strength values were observed in specimen compressed at 45◦ to axis of ECA pressed specimens. It was observed that mechanical properties after ECAP depend upon the strain path used in subsequent deformation. © 2007 Elsevier B.V. All rights reserved. Keywords: Equal channel angular pressing; Aluminum alloys; Mechanical properties; Strain path change 1. Introduction The microstructure produced after ECAP is highly inhomo- geneous with anisotropy in mechanical