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In the present investigation, machining performance of Ti6Al4V is studied under dry environment, pressurized air supply and distilled water based Minimum Quantity Lubrication (MQL). Machining (turning) performance is assessed in purview of cutting force (tangential component) magnitude, tool-tip temperature, width of tool flank wear progression, morphology of evolved chips and severity of vibrations at varied cutting speeds as well as cooling media. Characteristic features of spatial temperature distribution profile (at the vicinity of tool-tip) as influenced by varied cooling media are studied with the help of thermographs of the cutting zone. Mechanisms of cutting tool wear are studied as well. It is experienced that amongst three cutting environments tested, application of water-MQL is beneficial for machining of Ti6Al4V at low cutting speed. Severity of vibrations gets 50.39% reduced during machining under water-MQL than dry condition. Consequently, as compared to dry machining, water-MQL causes 79% reduced tool flank wear and 82% reduced crater wear at low cutting speed. Under water-MQL, reduced tool-tip temperature (66% reduced than dry condition) suppresses severity of tool wear. In comparison with high cutting speed, performance of water-MQL is found much better at low cutting speed. 'Unaffected zones' are identified at the worn-out tool rake face under water-MQL. High amplitude of vibration (maximum absolute mean value) causes low chip-segmentation ratio. On the contrary, chip reduction coefficient gets truncated with decrement in vibration amplitude. Vibration amplitude has positive influence on degree of chip-curl. [ABSTRACT FROM AUTHOR]

Since the 1960s, the Inconel Alloy 718 has been a standard nickel-based superalloy due to its high strength, balanced mechanical properties, and strong corrosion resistance at relatively low costs and has been widely used in critical aircraft engine components. With the aim of improving productivity and product quality by implementing advanced tools and new process designs, models such as the FE model are utilized to predict the machining performance such as the cutting forces, the tool life, and the surface integrity. In the research area of FEM chip formation simulation, the influence of flank wear on predictions has not been investigated, especially not on the underestimation of the cutting normal force. In this paper, a 2D FEM chip formation model with the coupled Eulerian-Lagrangian (CEL) method has been built to predict cutting forces as well as other material loadings (Brinksmeier et al. Procedia CIRP 13:429–434, 2014; Buchkremer and Klocke Wear 376-377:1156–1163, 2017) in the machining of Direct Aged 718. In order to validate the performance of the FE model, fundamental investigations have been performed in orthogonal cutting with different cutting parameters. Two kinds of cemented carbide cutting tools with different cobalt contents have been applied to achieve different tool wear behaviors. Moreover, the underestimation of the cutting normal force by FEM chip formation simulation has been investigated and solved in consideration of the flank wear. The introduced FE-modeling approach shows precise predictions in terms of the cutting forces and the chip formation. [ABSTRACT FROM AUTHOR]