Twinning plays an important role in governing the balance between strength and ductility in hexagonal-close-packed (HCP) metals. Here, we report a combined experimental and theoretical study of twin nucleation from a single lt c+a > dislocation in HCP crystals. Specifically, high-resolution transmission electron microscopy has been used to identify {11 (2) over bar1} twin nuclei in HCP rhenium, providing evidence of their nucleation from a lt c+a > dislocation. The favorability of this dislocation-based nucleation mechanism is rationalized by an anisotropic elasticity model of lt c+a > dislocation dissociation, parametrized by density functional theory calculations, which suggests the conditions for disconnection nucleation and propagation, under which this {11 (2) over bar1} twinning mechanism is expected to be effective. The analysis serves to advance our understanding of the origin of the unique predominance of {11 (2) over bar1} twinning in rhenium, which correlates with the ...high strength and ductility featured by this metal. It also provides new insights into design strategies that may be effective in activating this twinning mode and enhancing the balance between strength and ductility in HCP alloys more broadly.
Keywords:
Twin nucleation / Density functional theory (DFT) / Anisotropic elasticity / HRTEM / HCP metals
TY - JOUR
AU - Jiang, Lu
AU - Radmilović, Velimir R.
AU - Sabisch, Julian E. C.
AU - Qi, Liang
AU - Minor, Andrew M.
AU - Chrzan, Daryl C.
AU - Asta, Mark
PY - 2021
UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4951
AB - Twinning plays an important role in governing the balance between strength and ductility in hexagonal-close-packed (HCP) metals. Here, we report a combined experimental and theoretical study of twin nucleation from a single lt c+a > dislocation in HCP crystals. Specifically, high-resolution transmission electron microscopy has been used to identify {11 (2) over bar1} twin nuclei in HCP rhenium, providing evidence of their nucleation from a lt c+a > dislocation. The favorability of this dislocation-based nucleation mechanism is rationalized by an anisotropic elasticity model of lt c+a > dislocation dissociation, parametrized by density functional theory calculations, which suggests the conditions for disconnection nucleation and propagation, under which this {11 (2) over bar1} twinning mechanism is expected to be effective. The analysis serves to advance our understanding of the origin of the unique predominance of {11 (2) over bar1} twinning in rhenium, which correlates with the high strength and ductility featured by this metal. It also provides new insights into design strategies that may be effective in activating this twinning mode and enhancing the balance between strength and ductility in HCP alloys more broadly.
T2 - Acta Materialia
T1 - Twin nucleation from a single lt c plus a > dislocation in hexagonal close-packed crystals
EP - 41
SP - 35
VL - 202
DO - 10.1016/j.actamat.2020.10.038
UR - conv_6009
ER -
@article{
author = "Jiang, Lu and Radmilović, Velimir R. and Sabisch, Julian E. C. and Qi, Liang and Minor, Andrew M. and Chrzan, Daryl C. and Asta, Mark",
year = "2021",
abstract = "Twinning plays an important role in governing the balance between strength and ductility in hexagonal-close-packed (HCP) metals. Here, we report a combined experimental and theoretical study of twin nucleation from a single lt c+a > dislocation in HCP crystals. Specifically, high-resolution transmission electron microscopy has been used to identify {11 (2) over bar1} twin nuclei in HCP rhenium, providing evidence of their nucleation from a lt c+a > dislocation. The favorability of this dislocation-based nucleation mechanism is rationalized by an anisotropic elasticity model of lt c+a > dislocation dissociation, parametrized by density functional theory calculations, which suggests the conditions for disconnection nucleation and propagation, under which this {11 (2) over bar1} twinning mechanism is expected to be effective. The analysis serves to advance our understanding of the origin of the unique predominance of {11 (2) over bar1} twinning in rhenium, which correlates with the high strength and ductility featured by this metal. It also provides new insights into design strategies that may be effective in activating this twinning mode and enhancing the balance between strength and ductility in HCP alloys more broadly.",
journal = "Acta Materialia",
title = "Twin nucleation from a single lt c plus a > dislocation in hexagonal close-packed crystals",
pages = "41-35",
volume = "202",
doi = "10.1016/j.actamat.2020.10.038",
url = "conv_6009"
}
Jiang, L., Radmilović, V. R., Sabisch, J. E. C., Qi, L., Minor, A. M., Chrzan, D. C.,& Asta, M.. (2021). Twin nucleation from a single lt c plus a > dislocation in hexagonal close-packed crystals. in Acta Materialia, 202, 35-41.
https://doi.org/10.1016/j.actamat.2020.10.038
conv_6009
Jiang L, Radmilović VR, Sabisch JEC, Qi L, Minor AM, Chrzan DC, Asta M. Twin nucleation from a single lt c plus a > dislocation in hexagonal close-packed crystals. in Acta Materialia. 2021;202:35-41.
doi:10.1016/j.actamat.2020.10.038
conv_6009 .
Jiang, Lu, Radmilović, Velimir R., Sabisch, Julian E. C., Qi, Liang, Minor, Andrew M., Chrzan, Daryl C., Asta, Mark, "Twin nucleation from a single lt c plus a > dislocation in hexagonal close-packed crystals" in Acta Materialia, 202 (2021):35-41,
https://doi.org/10.1016/j.actamat.2020.10.038 .,
conv_6009 .
