Influence of cutting parameters on PCD tool wear during milling tungsten carbide

Tungsten carbide is known as an essential material for manufacturing industrial molds and tools owing to its excellent mechanical properties. However, the high-efficiency finishing of tungsten carbide is yet a challenge for it is extremely difficult to cut. This study investigates the influence of feed per tooth, radial cutting depth, and cutting speed on the wear of the PCD tool and the surface quality in dry milling of WC-15Co tungsten carbide. Experimental results showed that the PCD tool presented the longest tool life when the feed per tooth and radial cutting depth were below 9 µm/z and 0.6 mm, respectively, with the milling speed controlled at around 300 m/min. The flank wear-width VB was within 20 µm, and the surface roughness Sa was below 1.5 µm after 360 mm3 of the workpiece was removed. The effect of cutting parameters on the tool wear and surface roughness follows the order: feed per tooth > radial cutting depth > milling speed. The main forms of tool wear were found to be diffusion wear, wear caused by hard particles (two-body wear and three-body wear), and obvious adhered layer due to Co binder adhering and stacking on the tool rake face. Micro-chipping on the tool edge is considered one of the major causes of the increase in surface roughness. The defects on the machined surface largely originated from the clustering and spalling of WC particles, and the grooves formed by hard cluster rolling and plowing during WC-15Co milling.