Performance and wear mechanisms of coated PCBN tools in high-speed turning superalloy GH4202

This paper contributes to broadening the knowledge regarding coated PCBN tool wear in the finish turning operations of nickel-based superalloy GH4202. Three different coating PCBN tools (uncoated, TiN, and TiAlN) were used for finishing turning of superalloy GH4202. Cutting tests were carried out at a wide range of cutting speeds (vc = 50–400 m/min). Two different cutting conditions (dry and wet cutting) were also introduced. Aspects of tool wear and generated surface quality were studied. It was found that the protective function of the coating was limited only to the low cutting speed range. EDS analysis was used to analyze the wear mechanism under different cutting speeds. Different coatings exhibited different performance under different working conditions. The TiN coating was the most sensitive to the cutting coolant, and the uncoated tool was the most stable. Significant deposition of wear products was observed at high cutting speeds with the addition of cutting coolant.