Modeling of the effect of the beta phase deformation on the alpha phase precipitation in near-beta titanium alloys

Julien da Costa Teixeira (1) , Benoît Appolaire (1) , Elisabeth Aeby-Gautier (1) , Sabine Denis (1) , Fabien Bruneseaux (1)

1 LSG2M - Laboratoire de Science et Génie des Matériaux et de Métallurgie

A model has been developed in order to describe the influence of a prior plastic deformation of the beta phase above the transus on the precipitation of the alpha phase occurring during a subsequent cooling. The model relies on the calculation of the nucleation and growth rates of the alpha precipitates at the grain boundaries, based on a model presented formerly. Two major modifications have been carried out: first, the geometrical representation of the beta microstructure accounts for subgrains resulting from the deformation process; second, the calculation of the nucleation rate is dependent on the conditions of the plastic deformation. A careful analysis of the main parameters of the model has led to distinguish between several assumptions: the Widmanstatten colonies are likely to cross the subgrains during their growth; and the critical width of the transition from the allotriomorphs to the Widmanstatten plates is likely to decrease when the misorientation angle of the grain boundary decreases. Calculations performed for assessing the influence of the strain and strain rate on the transformation kinetics are in good agreement with previous measurements.

Mots clés: titanium alloys; simulation; nucleation; kinetics; plastic deformation

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Matériaux; Matériaux

Julien da Costa Teixeira, Benoît Appolaire, Elisabeth Aeby-Gautier, Sabine Denis, Fabien Bruneseaux. Modeling of the effect of the beta phase deformation on the alpha phase precipitation in near-beta titanium alloys. Acta Materialia, 2006, 54, pp.4261. ⟨10.1016/j.actamat.2006.05.019⟩. ⟨hal-00163456⟩