Nanoindentation-driven heterogeneous deformation and phase transformation in dual-phase RB-SiC: Insights from molecular dynamics

Reaction-bonded silicon carbide (RB-SiC) is an important dual-phase ceramic material for precision engineering. Due to limitations in nanoindentation experiments for observing the nanoscale characteristics of RB-SiC during indentation, many molecular dynamics (MD) studies have been conducted to investigate the deformation behavior of silicon (Si) and silicon carbide (SiC) at the atomic scale, primarily on single-phase materials. However, nanoindentation simulation analysis of RB-SiC has not been conducted in previous studies. In this work, MD simulations are conducted to investigate the heterogeneous deformation and phase transformation mechanisms in dual-phase RB-SiC, with nanoindentation experiments employed to provide qualitative corroboration of the simulation findings. Atomic-scale models of the Si-SiC and SiC-Si models are created. The results indicate that, compared to pure Si, the Si-SiC model has a higher load capacity, and the SiC-Si model shows reduced load capacity relative to pure SiC. The crack appearance and deformation mechanisms observed in the MD simulations are consistent with the surface topography characterized by Atomic Force Microscopy (AFM) after nanoindentation experiments. Furthermore, the phase transformation characteristics predicted by the model are consistent with the results detected by Raman spectroscopy. This study contributes to understanding the heterogeneous deformation and phase transformation mechanisms in dual-phase RB-SiC.