Tool wear analysis on coated and uncoated carbide tools in inconel machining

The aerospace industry has increasingly been using materials that have outstanding mechanical properties such as high strength, thermal and chemical resistance. Inconel 718 has been considered ideal material for hot and corrosive environments like aircraft jetengines. However, Inconel is difficult to machine due to its high toughness, low thermal conductivity and work-hardening during cutting. In this regard, the cutting speed for Inconel cannot be higher because tool chipping, notching and excessive wear occur at high cutting speeds. In this study, machining methods such as minimum quantity lubrication (MQL) with and without nano-particles, and cryogenic treated cutting tools have been applied for Inconel machining. Tool wear in these conditions are analyzed and compared with that of traditional machining methods, dry and wet machining. Coated and uncoated carbide tools are used to evaluate the coating effect associated with the machining methods. From the experimental results, surprisingly, the dry and wet machining outperformed both MQL and MQL with nano-particles in terms of tool wear. The cryogenic treated tool showed stable tool wear without severe edge fracture due to cryogenic hardening of the cutting tool while the MQL and Nano-MQL fractured severely, and the uncoated carbide tool performed better than the coated one.