Investigation of the material removal process in in-situ laser-assisted diamond cutting of reaction-bonded silicon carbide

Reaction-bonded silicon carbide (RB-SiC) is an important optical material used widely in the aerospace industry. The machining accuracy of RB-SiC optical elements must satisfy the requirements of high-performance system development. However, RB-SiC is typically hard and brittle, making precise machining difficult. Thus, the material removal and synergistic deformation mechanisms of SiC and silicon (Si) must be investigated for ultraprecision machining. In-situ laser-assisted diamond cutting is an effective method for the ultraprecision cutting of hard and brittle materials. In this research, we investigated the influence of temperature on the material deformation process in detail. Firstly, the physical properties of RB-SiC, including its hardness and depth of plastic deformation, were investigated through high-temperature nano-indentation experiments. Furthermore, grooving experiments were carried out to investigate the brittle-to-ductile transition under ordinary and in-situ laser-assisted diamond cutting, respectively. Finally, the deformation of the machined surface/subsurface was revealed via scanning electron microscopy and transmission electron microscopy observations.