LAUSR

Abstract Owing to high hardness and high brittleness of SiC ceramic, it is difficult to machine into structural ceramic components with desired surface quality and dimensional accuracy. In this paper, a method of polishing SiC ceramic by underwater femtosecond laser was proposed. The influence of laser frequency and pulse energy on surface morphologies, 3 D profiles, depth and surface roughness of polished SiC ceramics during underwater femtosecond laser processing was investigated in detail. The experimental results indicated that the removal depth during underwater polishing increased and then decreased with the increase of laser frequency and pulse energy. The surface roughness increased as laser frequency increased. The surface roughness decreased and then increased with the increase of pulse energy. Through laser parameter optimization, a high quality polished surface without cracks, pits and debris redopesition was obtained under laser frequency of 40 kHz and pulse energy of 40 μJ. At this point, the average removal depth of 32.19 μm and the average surface roughness of 0.72 μm were obtained. The proposed method in this paper significantly improve surface finishment and higher dimensional accuracy of the machined SiC ceramic components.