Atomistic simulations of twin boundary effect on the crack growth behaviour in BCC Fe

Abstract

In this paper, the effect of twin boundaries on the crack growth behaviour of single crystal BCC Fe has been investigated using molecular dynamics simulations. The growth of an atomically sharp crack with an orientation of (111)$<$110$>$ (crack plane/crack front) has been studied under mode-I loading at constant strain rate. In order to study the influence of twin boundaries on the crack growth behaviour, single and multiple twin boundaries were introduced perpendicular to crack growth direction. The results indicate that the (111)$<$110$>$ crack in single crystal BCC Fe grows in brittle manner. However, following the introduction of twin boundaries, a noticeable plastic deformation has been observed at the crack tip. Further, increasing the number of twin boundaries increased the amount of plastic deformation leading to better crack resistance and high failure strains. Finally, an interesting relationship has been observed between the crack growth rate and flow stress.

9 Pages, 6 Figures

References in corpus (4)

• Atomistic simulations on ductile-brittle transition in <111> BCC Fe nanowires
• Deformation behaviour of body centered cubic iron nanopillars containing coherent twin boundaries
• Directional Anisotropy of Crack Propagation Along $\Sigma$3 Grain Boundary in BCC Fe
• Role of twin boundary position on the yield strength of Cu nanopillars

Cited by in corpus (1)

• Twin interaction with $\Sigma$11 tilt grain boundaries in BCC Fe : Formation of new grain boundaries