Threshold Stress for Superplastic Flow in the Zn–Al Eutectoid Alloy
1993; Japan Institute of Metals; Volume: 34; Issue: 4 Linguagem: Inglês
10.2320/matertrans1989.34.319
ISSN2432-471X
Autores Tópico(s)Metallurgy and Material Forming
ResumoThe high temperature deformation of a commercial Zn–Al eutectoid alloy was investigated over the grain size range of 0.8 to 2.6 μm and the temperature range of 423 to 473 K, with a view to assessing the interpretation of region I in terms of a threshold stress for superplastic flow. The threshold stress evaluated by an extrapolation procedure is observed to decrease with increasing temperature and grain size. The activation energy and grain size exponent for the threshold process are 34 kJ/mol and 0.85, respectively. Boundary sliding controlled by boundary migration is the likely origin of the threshold stress.
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