The highlights of the manuscript include the following two aspects.

First, we found that the different machining modes (helical line scanning and single ring line scanning) and processing power of machining have remarkable effect on the surface morphology of the machined area, such as the shape, depth and the formation of different surface structures.

Secondly, we investigated that the debris consisted of C, Si and O was observed on the machined surface.

Some of the Si–C bonds of the SiC matrix and fibers would be transformed into Si–O bonds after machined, depending on the processing power.