Publications
Influence of temperature on void collapse in single crystal nickel under hydrostatic compression
M. Ramaswamy Guru Prasad, A. Neogi, N. Vajragupta, R. Janisch, A. Hartmaier.
Materials, 14, 2369, (2021)
Abstract
Employing atomistic simulations, we investigated the void collapse mechanisms in single
crystal Ni during hydrostatic compression and explored how the atomistic mechanisms of void
collapse are influenced by temperature. Our results suggest that the emission and associated mu-
tual interactions of dislocation loops around the void is the primary mechanism of void collapse,
irrespective of the temperature. The rate of void collapse is almost insensitive to the temperature,
and the process is not thermally activated until a high temperature ( ∼ 1200–1500 K) is reached. Our
simulations reveal that, at elevated temperatures, dislocation motion is assisted by vacancy diffusion
and consequently the void is observed to collapse continuously without showing appreciable strain
hardening around it. In contrast, at low and ambient temperatures (1 and 300 K), void collapse is
delayed after an initial stage of closure due to significant strain hardening around the void. Further-
more, we observe that the dislocation network produced during void collapse remains the sample
even after complete void collapse, as was observed in a recent experiment of nickel-base superalloy
after hot isostatic pressing.
Keyword(s): molecular dynamics; void; hot isostatic pressing (hip);
Cite as: https://www.mdpi.com/1996-1944/14/9/2369/htm
DOI: https://doi.org/10.3390/ma14092369
Download BibTEX
