Effect of cryogenic coolant on machinability of difficult-to-machine Ni–Cr alloy using PVD-TiAlN coated WC tool

Abstract

Abstract: Alloys of nickel are optimal metals to use in turbine parts and aircraft components. They are generally accepted as difficult-to-machine materials, because of its poor thermal conductivity. The selection of coolant and machining conditions is crucial for better performance. Problems with conventional coolant are failure of lubrication at higher metal removal and cause environmental pollution. The heat produced at the cutting zone can shorten the life of the tool, which leads to dimensional imprecision. The current experimental investigation is machining of Nimonic 80A under the effect of cryogenic liquid carbon dioxide (− 79.5 °C) using PVD-TiAlN coated tungsten carbide (WC) insert, which is compared with conventional dry, flood, and MQL environments. The machining is carried at varying cutting speed ranging from 45 to 90 m/min, a feed rate of 0.06–0.08 mm/tooth, and a constant depth of cut of 0.75 mm. The results admitted that cryogenic cooling lessens the average roughness by 42–47% over dry cutting, 24–27% over wet cutting, and 16–21% over MQL. It is proved that cryogenic cooling produces greater compressive stress on the machined surface and brings down the flank wear by decreasing the temperature on the cutting zone. Graphical abstract: [Figure not available: see fulltext.].