CALPHAD based kinetic Monte-Carlo simulation of clustering in binary Al-Cu alloy

Frédéric de Geuser (1) , Brian M. Gable (2) , Barry C Muddle (2)

1 SIMaP - Science et Ingénierie des Matériaux et Procédés
2 ARC Centre of Excellence for Design in Light Metals

A multi-body atomistic model has been developed for precipitation within a FCC substitutional aluminium alloy based upon the CALPHAD thermodynamic databases. Combined with diffusivity data, the model is applied to kinetic Monte-Carlo simulation of solute Cu clustering in a binary Al-Cu alloy. Both pairwise and four-body interactions are employed and it is demonstrated that, although limited to next nearest neighbour distances, the multi-body description result in features that resemble Guinier-Preston (GP) zones. It is not necessary to explicitly introduce long-range elastic interactions to simulate the monoatomic planar dimensions, form and crystallography of GP zones because these effects are inherently captured in the CALPHAD phase descriptions. This result shows that, although long range interactions are believed to be crucial in the formation of planar features such as GP-zones, first nearest neighbours multi-body interactions could, in principle, explain their appearance. The model is potentially readily generalised to multi-component alloys.

Mots clés: Physical Sciences

Domaines: Matériaux

Frédéric de Geuser, Brian M. Gable, Barry C Muddle. CALPHAD based kinetic Monte-Carlo simulation of clustering in binary Al-Cu alloy. Philosophical Magazine, 2010, 91 (2), pp.327. ⟨10.1080/14786435.2010.519354⟩. ⟨hal-00631268⟩