Investigation on crater morphology by high repetitive rate YAG laser-induced discharge texturing

An innovative texturing technique, high repetitive rate YAG laser-induced discharge texturing (LIDT), has been developed. The principle is a laser pulse synchronized with electrical pulse radiates on one of two electrodes, a plasma plume appears, that serves as discharge channel and the breakdown may occur between the electrodes far below the breakdown threshold. If the roll and a conical metal rod are the two electrodes, with the rotating of roll and the moving of laser set and conical metal rod along the axial of the roll, the deterministic or the random crater patterns are obtained on the roll surface by a serial laser-induced discharge. The experiments were carried out in different current discharge waveforms, media and electrical polarities on several materials. The results show that crater morphology is mainly determined by electrical polarity and medium. Simple explanations of the result are suggested.