Microhole drilling in TiC ceramic with a femtosecond pulsed laser

A femtosecond (fs) pulsed laser was employed to drill microholes in TiC ceramic. The Morphologies of microholes drilled at different assisted gas pressures and laser feeding speeds were investigated. Chemical compositions and chemical bonds of laser treated debris and untreated specimen were analysed. The mechanism of interaction between the femtosecond laser and the TiC ceramic was discussed. The results indicated that the assisted gas pressure had a greater effect on the morphologies of microholes, compared with the feeding speed. The entrance diameter of microholes was smaller than the exit diameter. The entrance roundness was more perfect than the exit roundness, and the entrance roundness decreased slightly with increasing gas pressure and feeding speed. Higher feeding speed was unfavourable to the morphologies of microholes. Ti, C and O were detected in laser treated debris. X-ray photoelectron spectroscopy (XPS) investigation showed that the C-Ti bond was broken and Ti₂O₃ and TiO₂ were formed during drilling.