Assessment of sustainable dry and MQL-assisted hard machining using MTCVD multilayered coated carbide (TiN/TiCN/Al2O3) insert

Abstract

ABSTRACT The application of minimum quantity lubrication (MQL) provides cooling, chip flushing and environment-friendly functions for sustainable manufacturing. Thus machinability study and surface characterisation of hardened AISI 4340 steel have been performed through multilayered coated MTCVD carbide (TiN/TiCN/Al2O3) insert under different cutting environments i.e. dry and MQL for sustainable machining. Flank wear in both cases (dry and MQL) is within the 0.2 mm failure criterion. Cutting speed influences more on flank wear more under dry conditions (65.26%), whereas depth-of-cut is for MQL (69.10%). Feed rate is the most significant parameter for surface roughness i.e. 73.40% and 75.96% contribution under dry and MQL, respectively. Average absolute errors for both artificial neural network (ANN) and regression models lie within 5%, with ANN giving better predictions. At 0.1 mm depth of cut, 0.04 mm/rev feed rate and 50 m/min cutting speed, tool life is 176.55 and 217.16 min (23% greater) in dry and MQL, respectively. In another condition of 0.1 mm depth of cut, 0.04 mm/rev feed rate and 100 m/min cutting speed, tool life under dry and MQL is 80.2 min and 131.2 min which contributes 63.6% greater than dry condition. MQL enhances the tool life and improves machinability and contributes towards sustainability.