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Although magnesium alloys deform extensively through shear strains and crystallographic re-orientations associated with the growth of twins, little is known about the strengthening mechanisms associated with this deformation mode. A crystal plasticity based phase field model for twinning is employed in this work to study the strengthening mechanisms resulting from the interaction between twin growth and precipitates. The full-field simulations reveal in great detail the pinning and de-pinning of a twin boundary at individual precipitates, resulting in a maximum resistance to twin growth when the precipitate is partially embedded in the twin. Furthermore, statistically representative precipitate distributions are used to systematically investigate the influence of key microstructural parameters such as precipitate orientation, volume fraction, size, and aspect ratio on the resistance to twin growth. The results indicate that the effective critical resolved shear stress (CRSS) for twin growth increases linearly with precipitate volume fraction and aspect ratio. For a constant volume fraction of precipitates, reduction of the precipitate size below a critical level produces a strong increase in the CRSS due to the Orowan-like strengthening mechanism between the twin interface and precipitates. Above this level the CRSS is size independent. The results are quantitatively and qualitatively comparable with experimental measurements and predictions of mean-field strengthening models. Based on the results, guidelines for the design of high strength magnesium alloys are discussed.

A chemo-mechanical model for a finite-strain elasto-viscoplastic material containing multiple chemical components is formulated and an efficient numerical implementation is developed to solve the resulting transport relations. The numerical solution relies on inverting the constitutive model for the chemical potential. In this work, a semi-analytical inversion for a general family of multi-component regular-solution chemical free energy models is derived. This is based on splitting the chemical free energy into a convex contribution, treated implicitly, and a non-convex contribution, treated explicitly. This results in a reformulation of the system transport equations in terms of the chemical potential rather than the composition as the independent field variable. The numerical conditioning of the reformulated system, discretised by finite elements, is shown to be significantly improved, and convergence to the Cahn-Hilliard solution is demonstrated for the case of binary spinodal decomposition. Chemo-mechanically coupled binary and ternary spinodal decomposition systems are then investigated to illustrate the effect of anisotropic elastic deformation and plastic relaxation of the resulting spinodal morphologies in more complex material systems.

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Predicting process–structure and structure–property relationships are the key tasks in materials science and engineering. Central to both research directions is the internal material structure. In the case of metallic materials for structural applications, this internal structure, the microstructure, is the collective ensemble of all equilibrium and nonequilibrium lattice imperfections. Continuum models to derive process–structure and structure–property relationships are based on two ingredients: 1) quantitative state variables that capture the essential features of the material's state and 2) kinetic equations for the state that describe its evolution under load. Successful models, that is, models that are of practical use, depend on state variables and corresponding evolution laws that are sufficiently representative for the microstructure and that are able to describe the phenomena of interest. The development of software tools capable to integrate these different aspects to get a holistic view of process–structure–property relationships requires joint efforts from specialists in different disciplines and a long‐term perspective. The Düsseldorf Advanced Material Simulation Kit (DAMASK) is such a tool. In this overview article published on the occasion of Advanced Engineering Materials' 20th anniversary, some representative application examples which demonstrate how DAMASK can be used to study metallic microstructures at different length scales are presented.

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