The effect of cutting speed and cutting tool geometry on machinability properties of nickel-base Inconel 718 super alloys

The effects of cutting speed and cutting tool geometry on cutting forces are investigated in this study. For this purpose, nickel-base super alloy, Inconel 718, is machined with dry cutting conditions by using digital controlled computer lathe with ceramic cutting tools in two different geometries and three different material qualities. Metal removing process is carried out for four different cutting speeds (150 m/min, 200 m/min, 250 m/min, and 300 m/min), while a cutting depth of 2 mm and a feed rate of 0.20 mm/rev are kept constant. As a result of the experiments, the lowest main cutting force, which depends on tool geometry, is obtained as 672 N with KYON 2100 SNGN 120712 ceramic tool and the maximum cutting force is determined as 1346 N with the ceramic cutting tool having KYON 4300 RNGN 120700 geometry. Depending on the cutting speed, the lowest main cutting force is recorded as 812 N at 250 m/min while the highest main cutting force is recorded as 955 N at 150 m/min. Plastic deformation, flank edge wear, notch and build-up edge are determined in high cutting speeds.