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, [S. l.], p. 438–449, 2022. DOI: 10.47750/pnr.2022.13.S04.048. Disponível em: https://www.pnrjournal.com/index.php/home/article/view/931.. Acesso em: 3 jun. 2026.