ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
In this paper, an ultra-fine grained AZ31 magnesium alloy sheet with grain size less than3μm was generated by three-run accumulative roll bonding of as cast alloy at a deformationtemperature of 350°C and a reduction of 80% for each pass. The microstructures on the different ARBstages were observed and superplasticity examination in the ultrafine grained AZ31 alloy were carriedout at a fixed temperature of 300°C and varied strain rate ranging from 10-4 to 10-1 s-1. It is indicatedthat significant grain refinement was mainly achieved in the first run and gradual uniformity of grainsize in the next by continuous dynamic recrystalization. Besides, a superplastic deformation with amoderate elongation-to-fracture of 316% was obtained at a strain rate of 10-2 s-1 indicating a lowtemperature and high strain rate superplasticity, while a maximum elongation-to-fracture of 562%at10-4 s-1. The strain rate sensitivity exponent as high as of 0.34-0.41 implies the dominant role ofgrain boundary sliding in superplastic deformation at strain rate ranging from 10-3 to 10-2 s-1. Theresults indicate a possible approach to produce magnesium alloy sheet with fine grain and excellentdeep drawing workability
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.551-552.249.pdf
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