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:
The superplasticity of a hot-rolled AZ31 Mg alloy was investigated by uniaxial tensile testsat temperature range 250-450oC and strain rate range 0.7×10-3-1.4×10-1s-1. Superplastic formability ofthe alloy was evaluated by gas bulging test at elevated temperatures. The threshold stress for grainboundary sliding (GBS) was calculated and the topography during superplastic deformation wasobserved by SEM. It is found that, at 400 oC and 0.7×10-3 s-1, the maximum elongation reaches362.5%. GBS is the predominant deformation mechanism and characterized by a pronouncedimprovement in homogeneity with increasing temperatures, indicating a transformation of GBS modefrom cooperative GBS (CGBS) to individual GBS (IGBS). The improved homogeneity of GBS canbe interpreted in terms of decreased threshold stress with increasing temperatures. Gas bulging testdemonstrates that the temperature for the best superplastic formability is 400 oC and a hemisphericalpart with a specific limiting dome height of 0.51 was obtained, suggesting good application prospectfor this alloy
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.551-552.231.pdf
Permalink