Investigations on the effect of nozzle angle and air flow rate during nanofluid Minimum Quantity Lubrication milling of Aerospace alloy Al7075-T6

Abstract

Present day industries are focusing upon finding various methods and techniques to implement sustainable manufacturing, which is 'the need of the hour'. With increase in global competition, industries are striving hard to reduce the machining costs, which is a major contributor for 'manufacturing cost per part', in an industry. Conventional method of using large quantity of coolant/cutting fluids in several liters per hour, to cool machining zone is causing enormous concern. Strict Government regulations are necessitating industries to replace flood-coolant assisted machining by new techniques like 'Minimum Quantity lubrication' (MQL) coolant supply technique. The present work deals with investigating the effect of varying nozzle angle and air-flow rate during MQL assisted surface milling of aerospace aluminum Al7075-T6 alloy, using uncoated carbide tool. Three methods of coolant supply namely Dry, MQL and nanofluid MQL (nano particles us pended oil with MQL) are experimented. Cutting speed [150m/min, 208m/min, 264 m/min], feed rate [95 mm/min, 110 mm/min, 125 mm/min] and depth of cut [0.5 mm, 1.3 mm, 2 mm] are chosen as process variables. Two nozzle angles 25C and 500, with 1.5 kg/cm2 and 3 kg/cm2 air flow rates were investigated. Best results were obtained for air flow rate of 1.5kg/cm2. Optimumnozzleangle was found to be 25C. To obtain lowest temperature and reduced heat generation, nanofluid MQL machining is a feasible option. With regards to MQL technique, for obtaining better surface finish with reduced surface roughness of the work piece (Al7075-T6), nanofluid MQL technique is best.