Dry Ultra-Precision Machining of Tungsten Carbide with Patterned nano PCD Tool

Texturing on the rake face of the tool without the metal working fluid is a potential method to reduce the friction coefficient in ultra-precision machining of tungsten carbide (WC) with a diamond tool. Low friction coefficient of the patterned tool would generate less heat in the tool-work interface and improve the tool life. This paper studies the effect of texturing on the cutting performance in ultra-precision machining of WC with a nano-polycrystalline diamond (PCD) tool. Orthogonal cutting experiments were conducted to verify the cutting performance of the textured diamond tool in machining of WC. The linear patterns parallel and perpendicular to the cutting direction were fabricated on the rake face of the nano-PCD tool by using the focused ion beam process. The experimental result showed that the friction coefficient of the perpendicular patterned tool decreased by 10%. WC surface machined with the patterned tool and non-patterned tool was also analyzed and compared. Material separation at grain boundary between tungsten grains and cobalt and full detachment of tungsten grains dominantly affected the surface quality of the machined WC surface.