Deformation twinning near to a crack tip was modelled, using molecular dynamics simulations, for body-centered cubic Mo under a loading rate of 0.0706MPam½/ps at 50K. The twinning behavior was governed by the crystal orientation and stress distribution. The width of the deformation twin band was affected by the distance between the upper and lower crack surfaces. The twin plane and twin direction were (1¯12) and [¯111], respectively. Initial crack extension occurred in the deformation twin region near to the crack tip. The simulation showed that the extension direction of the crack changed as the crack propagated over the twinning boundary.

Deformation Twinning and its Effect on Crack Extension Q.H.Tang, T.C.Wang: Acta Materialia, 1998, 46[15], 5313-21