Microstructures and mechanical properties of equal channel angular pressed5083 Al alloy

Citation
Sy. Chang et al., Microstructures and mechanical properties of equal channel angular pressed5083 Al alloy, MATER TRANS, 42(6), 2001, pp. 1074-1080
Citations number
58
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Material Science & Engineering
Journal title
MATERIALS TRANSACTIONS
ISSN journal
1345-9678 → ACNP
Volume
42
Issue
6
Year of publication
2001
Pages
1074 - 1080
Database
ISI
SICI code
1345-9678(200106)42:6<1074:MAMPOE>2.0.ZU;2-V
Abstract
An ultra-fine grained (UFG) structure was introduced in a commercial 5083 A l alloy with an initial grain size of similar to 200 mum using the equal ch annel angular pressing (ECAP) technique. ECAP was successfully conducted at 473 K on the same sample up to a total of 8 pressings through the die such that the sample was rotated 180 degrees around its longitudinal axis betwe en pressings. The microstructure was reasonably homogeneous after a single pressing and consisted of parallel bands of elongated substructure having a n average width of 0.2 mum and an average length of 0.8 mum. An equiaxed ul tra-fine grained structure of similar to 0.3 mum was obtained in the presen t alloy after 4 pressings. The ultra-fine grains were thermally stable at 5 23 K. The yield stress of as-received 5083 Al alloy was 129 MPa, whereas it increased to 249 MPa after a single pressing and finally became 290 MPa af ter 8 pressings, which was superior to that of a conventional 5083-H321 Al alloy. In addition, in this study, the feasibility of low temperature super plasticity of a UFG 5083 Al alloy was examined. It was found that the 5083 Al alloy with a grain size of similar to 0.3 mum exhibited a superplastic-l ike behavior with elongation to failure in excess of 200% below 523 It.