The role of hydrogen on the behavior of intergranular cracks in bicrystalline α-fe nanowires
Publication Name
Nanomaterials
Abstract
Hydrogen embrittlement (HE) has been extensively studied in bulk materials. However, little is known about the role of H on the plastic deformation and fracture mechanisms of nanoscale materials such as nanowires. In this study, molecular dynamics simulations are employed to study the influence of H segregation on the behavior of intergranular cracks in bicrystalline α-Fe nan-owires. The results demonstrate that segregated H atoms have weak embrittling effects on the pre-dicted ductile cracks along the GBs, but favor the cleavage process of intergranular cracks in the theoretically brittle directions. Furthermore, it is revealed that cyclic loading can promote the H accumulation into the GB region ahead of the crack tip and overcome crack trapping, thus inducing a ductile-to-brittle transformation. This information will deepen our understanding on the experi-mentally-observed H-assisted brittle cleavage failure and have implications for designing new nanocrystalline materials with high resistance to HE.
Open Access Status
This publication may be available as open access
Volume
11
Issue
2
Article Number
294
First Page
1
Last Page
15
Funding Number
DP170103092
Funding Sponsor
Australian Research Council