Assessment machining of micro-channel textures on PCD by laser-induced plasma and ultra-short pulsed laser ablation

Abstract Micro-channels are one of the most common surface textures for applications, however, the machining of micro-channels on polycrystalline diamond (PCD) is still facing challenges due to its intrinsic properties of high brittleness and hardness. In this paper, fabrication of micro-channels by laser induced plasma (LIP) and laser ablation directly (LAD) machining methods on PCD surface is experimentally investigated. For comparing the processing capacity, the influence of different laser process parameters (including overlap, power, frequency, scanning speed and the number of passes) on the geometry and material removal rate of micro-channels is assessed. Results show that the process parameters have a significant influence on the formation of micro-channels, and LIP exhibits higher efficiency compared to LAD in the case of the plasma formation with the high overlap and laser power. The micro-channel depth and width produced by LIP increase with the increasing overlap, laser power and number passes, and that reduce with the increasing frequency and scanning speed; the MRR produced by LIP increases with the increasing overlap, laser power and scanning speed, and that reduces with the increasing frequency and number of passes. Meanwhile, LIP reduces the oxidation reaction inside the micro-channels compared to LAD due to the shielding effect of distilled water.