N K Mandal et al IJMEIT Volume 05 Issue 06 June 2017 Page 1639 IJMEIT// Vol.05 Issue 06//June//Page No: 1639-1650//ISSN-2348-196x 2017 Index Copernicus Value-63.45 Determination of Optimum Parameters for Multi Performance in a Machining Process Authors N K Mandal 1 , N K Singh 2 , UC Kumar 3 1,3 National Institute of Technical Teachers’ Training and Research Block- FC, Sector-III, Salt Lake City, Kolkata- 700106 2 Indian Institute of Technology (ISM), Dhanbad - 826004 Jharkhand E mail: nkmandal@nitttrkol.ac.in, udaychandkumar@yahoo.com, nks_221@yahoo.co.in *Corresponding Author's N K Mandal E-mail: nkmandal@nitttrkol.ac.in ABSTRACT: Surface roughness is a very important parameter which have direct relationship with frictional losses of the mating components. If the frictional losses is more, the machine becomes less efficient. Turning is a widely used machining process for rotational jobs where excess material is removed in the form of chips by a single point cutting tool. There are basically two types of modelling: analytical modelling and empirical modelling, Scientists are mostly believing on analytical modelling where only controllable factors of a process are taken into account and does not tell anything about uncontrollable factors like vibration, tool wear etc. whereas Engineers believe on Empirical modelling where both controllable and uncontrollable factors of a process are considered. Theoretical modelling of any machining process is based on some theoretical knowledge. Some cutting phenomena have been modelled quantitatively and others qualitatively. Heuristic knowledge and skills of machinist is still needed to optimize the machining conditions in manufacturing systems. In this case, Grey Relational Analyses are used to find out the best combination of cutting parameters for maximum surface finish and minimum power consumption. Keywords: Turning, Power, Surface Roughness, Multi Objective Optimization, Grey Relational Analysis INTRODUCTION Turning centre is a special type lathe machine where multiple turning operations can be performed in a single set up. Turning is a machining operation where excess material is removed by a single point cutting tool using shear force. The turning process can be of different types like straight turning, taper turning, or exterior grooving etc. Axis motors and spindle motor which are attached to the spindle and lead screw provide power to turn the work piece at a given rotational speed, feed, and cutting speed. Fig. 1 Component of forces in turning operation In Fig. 1, for one revolution of the cylindrical bar, the tool moves in axial distance i.e. the feed distance (f), to reduce the bar radius by an amount of d i.e. the depth of cut. The Fig. 1 also shows the cutting force Fc acting on the tool, the diameter D at which the cutting is taking place and both the angular speed N at which the bar rotates and the linear speed. The torque and power supplied by Tool Cutting force, F c D N d V