Assessment of cyclic utilization of coated cemented carbide inserts for turning of Inconel 718

The cyclic utilization of coated cemented carbide inserts for turning of Inconel 718 was presented, which could be described as that the worn inserts should be given priority to repair rather than to reclaim the resources of W and Co. The assessment of the cyclic utilization was based on the fuzzy matter element (FME) according to the cutting performance including productivity, tool life, cutting forces, surface roughness, and wear mechanisms. From the productivity view accompanied with a rational tool life, the recommended cutting speed for coated cemented carbide and welding PCBN tools should be lower than 55 m/min and 92 m/min, respectively. With the cutting speed increasing, the amount of material removal of coated cemented carbide tools corresponding to the wear criterion of VB = 0.3 mm changed from 35 to 16.5 cm3, while that of welding PCBN tools varied from 25.5 to 18.6 cm3. Higher machining speed with the chamfered cutting edge for the welding PCBN tools enhanced the workpiece softening accompanied with better heat resistance, acquiring lower cutting force and better surface roughness. The dominant wear mechanisms of coated cemented carbide tools were notch wear under the lower cutting speed, while the adhesive wear became the leading factor when the speed was above 50 m/min. The welding PCBN tools showed severe wear pattern with adhesion, notching, and chipping. Based on the FME, the assessment of cutting performance demonstrated that the welding PCBN tools were better, which proved that the cyclic utilization was meaningful and improved the utilization efficiency of the worn cemented carbide inserts.