Turning of Inconel 718 with whisker-reinforced ceramic tools applying vegetable-based cutting fluid mixed with solid lubricants by MQL

The rule of thumb in the machining of nickel base superalloys with ceramic tools is to cut dry and no attempt of applying MQL with the addition of solid lubricant was made, according to the literature consulted. The main objective of this study is to evaluate the effect of the addition of solid lubricant in vegetal base oil applied by MQL (Minimum Quantity of Lubricant), when turning Inconel 718, with whisker-reinforced ceramic cutting tools (Al(2)O3 + SiCw). Tool life, tool wear mechanisms, surface integrity (microhardness, microstructure and roughness) and cutting force were evaluated. The results showed that the addition of MoS2 substantially improved tool life; types of dominant wear were the notch, flank and small crater, while the main wear mechanisms observed were adhesion and abrasion; cutting fluids improved the surface quality, Ra, and better results were found using vegetal base oil + 20% of graphite; as to the cutting force, the lubricants produced the lowest values.