Applications of scale-bridging to computational materials design

摘要

Computational materials design requires first the ability to predict the crystal structure and phase stability of yet to be discovered compounds and second the evaluation and prediction of materials properties and performance on the application scale. For many engineering applications processing for the control of microstructural elements is the key factor for achieving the desired performance on the continuum scale. From a modelling perspective, this second step in materials design requires an inherently scale-bridging approach: the quantum world that shows up in the bond formation between atoms needs to be coarse grained for a classical description of atomic interactions, then vast numbers of discrete atomic trajectories must form the basis for a continuum description of the material. This poses two questions of immediate relevance: how can the transition from a quantum mechanical description of the interatomic interaction to point-like atoms that interact with classical potentials be achieved in a systematic way? Next, how can results from atomistic simulations be used to devise and parametrize models on the continuum scale? In this focus collection, aspects of these two critical questions are discussed and reviewed. Magnetism and the repulsive contribution to the interatomic interaction is used as an example to demonstrate the coarse graining of a quantum mechanical description into a classical model. Phase boundaries are then used to illustrate the interface between atomistic and continuum modelling hierarchies. Phase-transformation modelling and continuum mechanics have to be unified and long-range transport due to convection has to be taken into account on the microscopic level. Aspects of numerical efficiency and a consistent constitutive framework are also addressed. The following special section of this journal has been compiled on the occasion of the five year anniversary of the foundation of ICAMS, the ‘Interdisciplinary Centre for Advanced Materials Simulation’ at the Ruhr-Universit?t Bochum, Germany. Researchers from ICAMS and other leading institutions around the world were invited to contribute to this collection, which includes the following eight focus papers and a topical review, ‘Atomistic simulations of grain and interphase boundary mobility’. All papers were peer-reviewed following the standard procedure established by the Editorial Board of Modelling and Simulation in Materials Science and Engineering. It would be impossible for this collection to serve as a comprehensive overview of the rapidly growing field of scale-bridging materials simulations, however it is our hope that it brings together key aspects that need to be considered for materials design from ‘atoms to components’.