Abstract: Ultra-short laser micromachining technology becomes the hottest research point in the field of micro manufacturing technology due to its unique advantages, especially for hard and brittle materials precision processing. By using the femtosecond laser micromachining system, the ablation characteristics and material removal mechanism of the wide band gap material SiC are theoretically and experimentally investigated. Scanning electron microscopy, atomic force microscope and optical microscopy are used to detect the ablation morphology of specimens so as to analyze the morphological characteristics and microstructure quality of ablation area. The ablation threshold of SiC material and the beam waist radius are obtained as 0.31 J/cm2 and 32 μm respectively on the basis of the functional relationship between ablation area and the laser energy. Besides, effects of pulse numbers, repetition rate and laser energy on the surface modification are explored, and a group of patterned microstructures are generated while their topography and the material removal mechanism are also analyzed, thus providing important guide for the precision machining of microstructures.

Key words: Ablation threshold, Femtosecond laser, Material removal mechanism, SiC