Experimental Investigation and Optimization of Flatness and Surface Roughness using Grey Relational Analysis for WCB Material during Face Milling Operation

The right selection of the machining process parameters may help to achieve the desired dimensional and geometric tolerances, to meet the functional requirements. In the present study to know the effect of machining parameters, during face milling operation, on surface roughness and flatness various experiments are performed by varying spindle speed, feed rate and depth of cut. The work piece material is Wrought Cast Steel grade B (WCB), as it widely used in manufacturing of valves due to its less cost. Experiments are performed using 23 full factorial designs with four centre points. The values of flatness and surface roughness are critical in the case of dual plate check valve, as it affects a lot during leakage testing. To achieve the desire value of flatness and surface roughness simultaneously machining parameters need to be controlled; hence the research is carried out and Grey Relational Analysis (GRA) of the data is carried out. The flatness and surface roughness is measured using CNC Coordinate Measuring Machine (CMM) and surface roughness tester respectively. The GRA gives the second run order as the optimized one. The second run order is having spindle speed of 1200 rpm, feed rate of 150 mm/min and dept of cut 0.1 mm. This run order gives the optimum value of surface roughness is 2.1035 mu m and flatness is 0.019 mm.