Material removal mechanism of 6H-SiC studied by nano-scratching with Berkovich indenter

The aim of this paper was to analyze the deformation characteristics and material removal mechanism of mono-crystal silicon carbide. The nano-scratching tests were conducted on the surface of 6H-SiC (0001) by using Berkovich nano-indenter. In the presence of various characterization techniques, a variety of new achievements have been reached. Phase transformation behavior in the nano-scratching process of mono-crystal silicon carbide (6H-SiC) is revealed by using the transmission electron microscope in this work. Amorphous phase and dislocation activities are found near the surface area under the bottom of the scratch which stands as the major cause triggering the plastic removal of this material, with no other forms of crystalline structure found, by which the plastic removal mechanism of mono-crystal silicon carbide was well identified. With a crack-free surface that had been processed, the chip broke away from the bulk in the form of plastic mode, but the subsurface was covered by cracks with their lengths many times longer than the machined depth. The results of laser Raman indicated that residual amorphous phase exits in the chips under the condition of the plastic removal of this material.