Phase-field-based chemomechanical models for phase transitions and dislocation-microstructure interaction in metallic alloys with application to kappa-carbides

拟议的工作是关注的制定，比较和应用相场为基础的化学力学模型的金属合金经历相变，位错介导的有限变形和故障。在方法学方面，这是基于例如现有方法的推广和进一步发展，如WBM（Wheeler-Böttinger-McFadden）和KKS（Kim-Kim-Suzuki），用于化学均匀化到大变形化学力学。这些将与现有的化学力学模型的背景下，例如基准模拟和过量的界面能建模的小变形进行比较。此外，基于人工和物理（即，亚晶格和元素位点分数为基础的）化学序参数将扩展到有限变形化学力学，促进耦合到CALPHAD。同样，位错过程和故障的建模将包括通过相场微弹性缺陷和相场断裂到有限变形的推广。所提出的方法和模型的发展的主要应用包括模拟沉淀，位错-溶质相互作用，位错-沉淀相互作用。在这方面特别感兴趣的是Fe-Mn-C-Al基低密度钢κ碳化物。

The proposed work is concerned with the formulation, comparison and application of phase-field-based chemomechanical models for metallic alloys undergoing phase transitions, dislocation-mediated finite deformation, and failure. On the methodological side, this is based for example on generalization and further development of existing approaches such as WBM (Wheeler-Böttinger-McFadden) and KKS (Kim-Kim-Suzuki) for chemical homogenization to large-deformation chemome-chanics. These will be compared with existing chemomechanical models for small deformation in the context for example of benchmark simulations and the modelling of excess interface energy. In addi-tion, models based on both artificial and physical (i.e., sublattice- and element-site-fraction-based) chemical order parameters will be extended to finite-deformation chemomechanics, facilitating cou-pling to CALPHAD. Likewise, the modelling of dislocation processes and failure will be included via the generalization of phase-field microelasticity for defects and phase-field fracture to finite defor-mation. Principle applications of the proposed method and model developments include the model-ling of precipitation, dislocation-solute interaction, and dislocation-precipitate interaction. Of par-ticular interest in this regard are Fe-Mn-C-Al-based low-density steel kappa-carbides.