Effect of water film on 4H-SiC nano-indentation process

4H-SiC is one of the most commonly used third-generation semiconductor materials, and the machining technology of it has always been a big problem. Considering that the actual machining process is often inseparable from water, it is necessary to study the mechanical properties and deformation behavior of 4H-SiC under wet conditions. Molecular dynamics simulation is used to study the influence of water film on the indentation process of 4H-SiC. It is found that the pop-in event during loading is related to the deformation mode of 4H-SiC. The plastic deformation of 4H-SiC is accompanied by phase transformation, which can partially release the stress. Water film can advance the pop-in event because the phase transformation will be intensified after water molecules are pressed in. Water film can also narrow the gap between the maximum and minimum values of pop-in events, but it will lead to more damage and greater damage depth after indentation. Besides, the unloading process is often accompanied by the recovery of damaged structures and the water film will reduce the SiC atoms adhered to the indenter during unloading.