Abstract
A study was carried out to investigate the mechanisms of superplastic deformation in two phase Ti-6Al-4V alloy. Tensile tests were carried out using fine (3 μm) and coarse (11 μm) grained microstructures at 600 and 900°C with a strain rate of 10-3S-1, and the quenched microstructures were analyzed by transmission electron microscopy. In the coarse grain microstructure, the planar arrays of dislocations were developed well in the α-phase both at 600 and 900°C. However, in the fine grain microstructure, dislocations were rarely observed in the α-phase at 600°C, while a few dislocations were observed near the α/β boundaries at 900°C. The results indicate that most of deformation is imposed on the β-phase in the fine grain microstructure, and on the α-phase as well as the β-phase in the coarse-grain microstructure. It is also considered that accommodation processes for phase/grain boundary sliding in the α and β phase are closely associated with the dislocation motion.
Original language | English |
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Pages (from-to) | 272-280 |
Number of pages | 9 |
Journal | Materials Science and Engineering: A |
Volume | 263 |
Issue number | 2 |
DOIs | |
State | Published - 15 May 1999 |