Investigation on Surface Roughness during Milling of AL-61 Machining under Minimum Quantity Lubrication (MQL)

In modern production industries, main focus is on high productivity with best surface finish. For this purpose use of cutting fluid in machining of component plays major role in controlling the surface finish of components. The cutting fluids are generally applied continually during machining i.e. wet or flooded machining. The dry machining yields poor surface finish and less tool life whereas wet machining results in better surface finish as well as longer tool life. But continuous lubrication involves very large amount of consumption of cutting fluids which cause health hazards of machining operator and ill effects on environment. Moreover, continuous lubrication contributes to increase in total production cost of product. Hence, the Minimum Quantity Lubrication(MQL) is needed nowadays which works with less amount of cutting fluid (100-1000ml/hr) with pressurized air (as mist form) as compare wet machining (amount of cutting fluid 400-500L/hr approx.). The study focus on comparison of surface roughness behavior of AL-6061 under different lubrication conditions i.e. Dry, Wet and MQL. The experimental work performed on CNC milling machine involving cutting parameters feed rate, spindle speed and depth of cut as input parameters, where surface roughness and microstructure of specimens were observed as output parameters in the experiment. The machined components under different conditions i.e. DCM (dry cutting machining), MQL (minimum quantity lubrication), WCM (wet cutting machining) were examined for surface roughness using R-10 surface roughness tester whereas microstructure analysis was done using optical microscope. For given cutting parameters at 2000RPM spindle speed, 200mm/min. feed rate and it is found that better result of MQL from the dry machining and nearest of wet machining.