Abstract
This paper presents the results of an experimental investigation for turning of Grade-4 titanium
with carbide cutting tool inserts with minimum quantity lubrication (MQL). Experiments were
designed based on Taguchi’s L9 orthogonal array. The MQL parameters of flow rate (50-70-90
mL/hr); nozzle distance (20-30-40 mm) and air pressure (4-5-6 bar) were varied for three different
levels each. Cutting speed, feed and depth of cut were fixed at 125 m/min; 0.2 mm/rev and 1 mm
respectively. The grey relational method in conjunction with the Taguchi technique was used for
optimizing the MQL parameters. The nozzle distance was recognized as the most significant
parameter. The data further indicated that the optimum MQL parameters were a flow rate of 70
mL/hr, nozzle distance of 30 mm and air pressure of 6 bar. When compared to dry and wet cutting
conditions MQL was shown to have significant advantages.