2022. A Novel Optimization of Feed and Spindle Speed Levels for Surface Roughness and Cylindricity Tolerance of the Drilled Holes in Liquid Stir Casted Al6061 Hybrid Metal Matrix Composite Reinforced with 15% Weight Fraction of B4C+Fly ash and Comparing with th. Journal of Pharmaceutical Negative Results. (Sep. 2022), 438–449. DOI:https://doi.org/10.47750/pnr.2022.13.S04.048.