In this talk, we will present a chemo-mechanical model for a finite-strain elasto-viscoplastic material containing multiple chemical components [1-3]. An efficient numerical implementation based on a semi-analytical inversion is developed to solve the resulting transport relations. We will then present its application in the modeling of multi-component phase precipitation in Al-Zn-Mg-Cu alloys and phase separation behaviour in battery positive electrode material (Li_XFePO₄). The complex compositional pathway for the formation of the η-phase in Al-Zn-Mg-Cu alloys during commercial multi-stage artificial ageing treatments is systematically studied. In particular, the influence of alloy composition, solute diffusivity, and heat treatment parameters on the microstructural and compositional evolution of η-phase precipitates, was investigated from a thermodynamic and kinetic perspective. Finally, we will present the influence of chemo-mechanical coupling, including chemical expansion, coherency strain and dislocations, on the phase separation behaviour and heterogeneities in the stain and stress distributions in Li_XFePO₄ single crystal cathode material.

[1] C. Liu, A. Davis, J. Fellowes, P.B. Prangnell, D. Raabe, P. Shanthraj, CALPHAD-informed phase-field model for two-sublattice phases based on chemical potentials: η-phase precipitation in Al-Zn-Mg-Cu alloys, Acta Mater. 226 (2022) 117602.

[2] C. Liu, A. Garner, H. Zhao, P.B. Prangnell, B. Gault, D. Raabe, P. Shanthraj, CALPHAD-informed phase-field modeling of grain boundary microchemistry and precipitation in Al-Zn-Mg-Cu alloys, Acta Mater. 214 (2021) 116966.

[3] P. Shanthraj, C. Liu, A. Akbarian, B. Svendsen, D. Raabe, Multi-component chemo-mechanics based on transport relations for the chemical potential, Comput. Methods Appl. Mech. Eng. 365 (2020) 113029.