Experimental Evaluation of Various Parameters Influencing Thrust Force, Torque and Circularity in Drilling of Al based Composites using Response Surface Methodology

Background/Objectives: The application of composite materials has been increasing worldwide in all manufacturing industries. In drilling operation, the quality of hole is the basic requirement in various applications. So, the selection of optimized drilling parameters is very important for the better hole quality. Our objective is to formulate a mathematical model using response surface methodology. Methods: A series of experiments are conducted using ARIX-CNC vertical machining center on Square slabs of size 100mm x 100mm x 10mm, fabricated by stir casting method. Our work is focusing on formulating the model to investigate the effects of various drilling parameters such as spindle speed (1000, 2000 & 3000rpm), feed (0.05, 0.1 & 0.15 mm/rev) and drill tool diameter (5, 7.5 & 10mm) on thrust force, torque and circularity in drilling of Al / SiC metal matrix composite and Al / SiC / Gr hybrid composite using solid carbide drills. Findings: The experimental results on drilling of the metal matrix and hybrid composites are collected separately on L27 orthogonal array and analyzed using Signal – Noise (S/N) ratio, the analysis of variance (ANOVA) and regression analysis with the help of Design expert software and Mathematical models are developed with an objective to correlate the selected drilling parameters with drilling force, torque and circularity error in drilled holes. ANOVA is used to reveal the dominant factors that affect the responses mentioned above. Application/Improvements: The developed models are significant and the predicted values are very close to the actual values. This model can be effectively used for drilling of Al/SiC metal matrix and Al/SiC/Gr Hybrid composites within the range of the process parameters.