Investigating Optimum Parameter Required for Drilling Mild Steel Using Response Surface Methodology (Published)
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
Comparison of Surface Roughness of Cold Work and Hot Work Tool Steels in Hard Turning (Published)
The hard turning process has been attracting interest in different industrial sectors for finishing operations of hard materials at its hardened state. Surface roughness is investigated in hard turning of AISI D3 and AISI H13 steels of same hardness 62HRC. In this paper, an attempt has been made to model and predict the surface roughness in hard turning of AISI D3 and AISI H13 hardened steels using Response Surface Methodology (RSM). The combined effects of three machining parameters such as cutting speed, feed rate and depth of cut are investigated for main performance characteristic that is surface roughness. RSM based Central Composite Design (CCD) is applied as an experimental design. Al2O3/TiC mixed ceramic tool with corner radius 0.8 mm is employed to accomplish 20 tests with six center points. The acceptability of the developed models is checked using Analysis of Variance (ANOVA).The combined effects of cutting speed; feed rate and depth of cut are investigated using surface plots.
Keywords: AISI D3, AISI H13, Hard turning, RSM and ANOVA, Surface Roughness