Multiscale analysis of crystal defect formation in rapid solidification of pure aluminium and aluminium-copper alloys

TL;DR

This paper presents a multiscale modeling approach to understand the formation of crystalline defects during rapid solidification of aluminum alloys, combining atomistic and continuum simulations for mechanistic insights.

Contribution

It introduces a multiscale framework integrating MD, PFC-AE, and PF-CP simulations to analyze defect formation mechanisms in rapid solidification.

Findings

Dislocation densities quantified and compared to experiments

Atomistic models calibrate continuum crystal plasticity models

Framework provides mechanistic insights into defect formation

Abstract

Rapid solidification leads to unique microstructural features, where a less studied topic is the formation of various crystalline defects, including high dislocation densities, as well as gradients and splitting of the crystalline orientation. As these defects critically affect the material's mechanical properties and performance features, it is important to understand the defect formation mechanisms, and how they depend on the solidification conditions and alloying. To illuminate the formation mechanisms of the rapid solidification induced crystalline defects, we conduct a multiscale modeling analysis consisting of bond-order potential based molecular dynamics (MD), phase field crystal based amplitude expansion (PFC-AE) simulations, and sequentially coupled phase field -- crystal plasticity (PF--CP) simulations. The resulting dislocation densities are quantified and compared to past experiments. The atomistic approaches (MD, PFC) can be used to calibrate continuum level crystal plasticity models, and the framework adds mechanistic insights arising from the multiscale analysis.