IMPACT OF VARYING THE NOZZLE STAND - OFF DISTANCE ON CUTTING TEMPERATURE IN TURNING OF EN-31 STEEL WITH MINIMUM QUANTITY LUBRICATION

Tool wear is a natural phenomenon in all metal cutting operations due to high friction at tool work interface, which affect the tool life, product quality and accuracy of work.For minimizing the friction at tool work interface the cutting fluids or lubricants are used for cooling and lubrication, hence improvement in machining efficiency.But if the quantity and quality of lubricants are unattended or underestimated then it creates problems like soil, water, environmental pollution and also makes the machining process uneconomical.The different cooling and lubrication techniques have been developed today.So it is necessity of present day scenario of machining to work with technology which would not degrade the environment, face the competition and have better quality of products.Different research shows that conventional Flood lubrication is limited by health hazards, misting and sometime uneconomical as compared to other techniques, due to its high discharge rate of fluid.These problems have been overcome by using dry machining.Studies shows that dry machining also becomes non efficient and uneconomical during cutting of harder materials at higher cutting speed, feed and depth of cut, although it is environmental friendly and economical at particular machining level.So to minimize all these Problems of health hazards, non-economy, intense tool wear in case of flood cooling and dry machining, the minimum quantity lubrication (MQL) has been applied in this present research.The effect of varying the nozzle stand-off distance and lubricant pressure have been considered in this study, to find out the best results in terms of cutting temperature.The experimentation has been conducted during turning of EN-31 Alloy Steel with minimum quantity lubrication at flow rate of 150 ml/hr having vegetable based oil.The temperature has been measured by K-type thermocouple .The vegetable oil has been selected due to its environmental friendly behavior and does not produce health hazards, like mineral oil during flood lubrication.