Wear behaviour of TiAlN coated solid carbide end-mill under alumina enriched minimum quantity palm oil-based lubricating condition

The lubricating effect of alumina deposited palm oil was investigated during the end-milling of Inconel 690. Different volume concentration (0.3-1.5%) of alumina was reinforced into palm oil, and experimentally optimized concentration of alumina was selected. Later on, the milling experiments were carried out in Flooded, MQL with palm oil (MPO) and MQL with 0.9% alumina enhanced palm oil (0.9%-MAPO) medium, which confirmed that 0.9%-MAPO reduced the tool wear by 19.35%, and 10.71% respectively as compared to flooded and MPO medium. SEM and EDX analysis demonstrated that adhesion and abrasion were the principal tool wear mechanism in all lubricating environments. Further analysis confirmed that 0.9%-MAPO medium effectively formed a surface protecting film on the machined surface.