Coupled phase-field and phase-field crystal studies to bridge the atomic to micro-scale in heterogenous nucleation

该项目的主要目标保持不变，即旨在有助于更全面地理解非均质成核和连续的初始微结构演变的动力学，因为它们是由原子尺度上的机制和远程贡献共同决定的，以及胶体中可识别的机制在多大程度上真正延续到金属合金系统的问题。为此目的，已经开始并将继续开发一个耦合的相场-场-晶体-相场模型来研究这些问题。鉴于在优先计划的第二阶段，重点放在不同模型贡献的技术开发和探索上，在优先计划的下一阶段，我们将利用我们迄今的发展，特别是与进一步的理论和实验小组密切合作，进一步研究系统的驱动力、成核率、非均质成核相(分别为一面墙)之间的失配和相关接触角之间的关系。后一种相互作用将有助于我们通过关闭和根据特定假设的潜在机制建立模型来详细确定这些机制。

The main goal of this project remains unaltered, i.e. it aims to contribute to a more comprehensive understanding of the kinetics of heterogeneous nucleation and successive initial microstructure evolution as they are determined jointly by mechanisms at the atomic scale and long range contributions, as well as the question, to what extend the mechanisms that can be identified in colloids truly carry over to metallic alloy systems. To that end a coupled phase-field crystal – phase-field model has been started to be and will be continued to be developed to investigate these issues. Whereas in the second phase of the priority program the focus was on the technical development and exploration of different model contributions, in this next phase of the priority program we will exploit our developments so far and investigate in particular the relation between the system’s driving force, the nucleation rate, the mismatch between the heterogeneously nucleating phases (respectively a wall) and related contact angles further in close cooperation with further theoretical and experimental groups. The latter interaction will help to us identify – via switching off and on terms modelling specific assumed underlying mechanisms – those mechanisms in detail.