Simulation of dendritic-eutectic growth with the phase-field method

TL;DR

This paper develops a phase-field model to simulate the coupled growth of dendritic and eutectic microstructures, providing insights into their morphologies and effects on material properties under various processing conditions.

Contribution

It introduces a novel phase-field model capable of reproducing dendritic, eutectic, and combined growth, filling a gap in understanding their coupled evolution.

Findings

Simulated all three microstructures depending on composition and conditions.

Analyzed the impact of growth modes on microstructural lengths.

Studied morphological hysteresis and effects of solidification velocity jumps.

Abstract

Solidification is an important process in many alloy processing routes. The solidified microstructure of alloys is usually made up of dendrites, eutectics or a combination of both. The evolving morphologies are largely determined by the solidification process and thus many materials properties are dependent on the processing conditions. While the growth of either type of microstructure is well-investigated, there is little information on the coupled growth of both microstructures. This work aims to close this gap by formulating a phase-field model capable of reproducing dendritic, eutectic as well as dendritic-eutectic growth. Following this, two-dimensional simulations are conducted which show all three types of microstructures depending on the composition and processing conditions. The effect of the dendritic-eutectic growth on the microstructural lengths, which determine materials properties, is investigated and the morphological hysteresis between eutectic growth and dendritic-eutectic growth is studied by employing solidification velocity jumps. Further, the influence of primary crystallization is investigated in large-scale two-dimensional simulations. Finally, qualitative three-dimensional simulations are conducted to test for morphological changes in the eutectic.