Abstract. Liquid metal embrittlement (LME) in the Al–Ga system is studied using molecular dynamics simulations. Crack tip opening loads are exerted on symmetric tilt Al bicrystals in the presence of liquid Ga. In general, the speed of crack propagation increases in the presence of Ga. However, there is significant variation in the dynamic behavior of the different boundaries studied here. We observe the formation of a sub-grain by grain boundary dissociation (grain boundary phase transformation) in [1 1 0] Σ9 and [1 1 0] Σ11 grain boundaries; this results in crack blunting even in the presence of Ga. In the Σ3 twin, the absence of alternating compressive and tensile stresses present in other boundaries results in fast Ga penetration after the crack path is formed. The structure of grain boundaries apart from thermodynamic considerations significantly affects LME.

Print publication: Issue 7 (October 2008)
Received 2 January 2008, in final form 3 July 2008
Published 3 September 2008