Ductile Regime Nanomachining of Single-Crystal Silicon Carbide

Abstract

We have demonstrated the ability to perform a ductile material removal operation, via single-point diamond turning, on single-crystal silicon carbide (6H). To our knowledge, this is the first reported work on the ductile machining of single-crystal silicon carbide (SiC). SiC experiences a ductile-to-brittle transition similar to other nominally brittle materials such as silicon, germanium, and silicon nitride. It is believed that the ductility of SiC during machining is due to the formation of a high-pressure phase at the cutting edge, which encompasses the chip formation zone and its associated material volume. This high-pressure phase transformation mechanism is similar to that found with other semiconductors and ceramics, leading to a plastic response rather than brittle fracture at small size scales.