Surface growth for molten silicon infiltration into carbon millimeter-sized channels: Lattice-Boltzmann simulations, experiments and models

TL;DR

This study combines experiments, simulations, and models to analyze molten silicon infiltration into carbon channels, highlighting surface growth effects, reaction mechanisms, and the effectiveness of Lattice-Boltzmann simulations in predicting the process.

Contribution

It develops a framework for evaluating simulation accuracy and integrates surface reaction effects into infiltration modeling, advancing understanding of reactive silicon infiltration.

Findings

Silicon carbide growth occurs in two stages.

Lattice-Boltzmann simulations accurately describe the growing phase.

Models can incorporate chemical reaction resistance into Darcy law.

Abstract

The process of liquid silicon infiltration is investigated for channels with radii from $0.25$ to $0.75$ [mm] drilled in compact carbon preforms. The advantage of this setup is that the study of the phenomenon results to be simplified. For comparison purposes, attempts are made in order to work out a framework for evaluating the accuracy of simulations. The approach relies on dimensionless numbers involving the properties of the surface reaction. It turns out that complex hydrodynamic behavior derived from second Newton law can be made consistent with Lattice-Boltzmann simulations. The experiments give clear evidence that the growth of silicon carbide proceeds in two different stages and basic mechanisms are highlighted. Lattice-Boltzmann simulations prove to be an effective tool for the description of the growing phase. Namely, essential experimental constraints can be implemented. As a result, the existing models are useful to gain more insight on the process of reactive infiltration into porous media in the first stage of penetration, i.e. up to pore closure because of surface growth. A way allowing to implement the resistance from chemical reaction in Darcy law is also proposed.