Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1575360 | Materials Science and Engineering: A | 2014 | 12 Pages |
Abstract
Uniaxial tensile tests of a typical Ni-based superalloy are conducted under the deformation temperature range of 920-1010 °C and strain rate range of 0.01-0.001 sâ1. The effects of initial δ phase (Ni3Nb) on the hot tensile deformation behaviors and fracture characteristics are discussed in detail. The results show that: (1) For the studied Ni-based superalloy with a large amount of δ phase, the flow stress curves are composed of three distinct stages, i.e., work hardening stage, flow softening stage and the final fracture stage. (2) The initial δ phase has significant effects on the deformation behaviors of the studied superalloy. δ phase can cause the obvious work hardening at the beginning of hot deformation, and then accelerates the flow softening by promoting the dynamic recrystallization with further straining. With the increase of initial δ phase, the strain rate sensitivity coefficient decreases firstly and then increases. (3) The combined effects of localized necking and microvoid coalescence cause the final fracture of specimens. The increase of initial δ phase increases the density of nucleus for the formation of microvoids, and promotes the nucleation and coalescence of microvoids.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Y.C. Lin, Jiao Deng, Yu-Qiang Jiang, Dong-Xu Wen, Guan Liu,