Experimental Investigation of the Surface Topography in Terms of Process Parameters During Picosecond Laser Machining of Polycrystalline Diamond

Abstract

Abstract Because of its significant impact on the friction and surface quality of a cutting process, the surface topography of the flank face is one of the most crucial indicators for the quality of Polycrystalline Diamond (PCD) cutting tools machined with ultrafast laser. Therefore, it is necessary to study the effect of process parameters on the topography of the machined surface. In this study, a picosecond laser with 1064nm wavelength was used to generate and polish kerfs on PCD samples. An orthogonal experiment was conducted to evaluate the impact of process parameters on surface roughness. The results indicated that the surface roughness decreased with increased pulse energy, polishing depth, or decreased laser polishing speed. As the number of polishing cycles increased, the surface roughness tended to first decrease and then increase. The results of variance analysis demonstrated that the polishing speed and polishing depth have a significant impact on the surface roughness. Additionally, surface topography and microgrooves formed on the side wall of the kerfs were studied using a digital microscope. Finally, process optimization was carried out based on the previous experiment. A surface roughness of Ra0.16μm was obtained and recasting layer was fully removed. This study shows that the surface topography of the flank face of PCD cutting tools can be improved with an appropriate combination of the cutting depth, cutting speed, number of polishing cycles, and pulse energy during ultrafast laser processing.