The study investigated on optimum parameters required for drilling mild steel using Response Surface Methodology (RSM) based on L9-A 34-2 fractional factorial design. The mild steel workpiece is of dimension of 200 mm by 80 mm with a thickness of 1.5 mm. The study employed the following process parameters namely, cutting speed, feed, depth of cut and tool for minimizing surface roughness of mild steel. Vertical pillar drilling machine of METALIK PK203 model was used for the drilling operation and coupling ultrasonic thickness meter of TM-8810 model was also used to measure the surface roughness of the workpiece after drilling. Analysis of Variance (ANOVA) was carried out to test for the significant level of the process parameters for optimizing surface roughness. The findings revealed that the process parameters has a high significant effect in influencing the response variable at 5% significant level and that optimum process parameters can be achieved at an intermediate level during drilling operation. The findings also revealed that there exist a good agreement between the estimated and experimental results based on the mathematical model formulated.
Keywords: ANOVA, Mild steel., Response Surface Methodology (RSM), Surface Roughness, process parameters
