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Tensile testing of Al6061-T6 microspecimens with ultrafine grained structure derived from machining-based SPD process

Published online by Cambridge University Press:  25 June 2014

Paresh S. Ghangrekar ,
Ramprakash Banjare ,
Balkrishna C. Rao  and
H. Murthy
Paresh S. Ghangrekar
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600036, India
Ramprakash Banjare
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600036, India
Balkrishna C. Rao
Affiliation:
Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
H. Murthy*
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600036, India
*
a) Address all correspondence to this author. e-mail: mhsn@ae.iitm.ac.in
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Abstract

This paper discusses tensile testing of small samples of nanocrystalline Al6061-T6 alloy obtained from an unusual application of machining as a severe plastic deformation process. Ultrafine grained (UFG) shavings obtained from plane-strain cutting show higher hardness than the bulk material in agreement with existing literature. Application of restricted contact tools and extrusion-machining was explored to obtain shavings with minimum curvature to aid in tensile test specimen preparation. A novel method to prepare small tensile test specimens from these shavings has been described. During the tensile testing of UFG material, strains were measured using digital image correlation of natural speckles on the specimen. Specimens made from the UFG material had higher tensile strength and yield stress than the bulk, while ductility was lower. Lower values of Young's modulus were observed during the tensile testing of small specimens made from UFG as well as bulk material.

Keywords

severe plastic deformation (SPD)Al6061machiningultrafine grainedstraight chipstensile strength
Type
Articles
Information
Journal of Materials Research , Volume 29 , Issue 11 , 14 June 2014 , pp. 1278 - 1287
Copyright
Copyright © Materials Research Society 2014 

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