Effects of some machining variables on tool wear, surface finish, dimensional error and cutting power in turning gray cast iron using CBN and ceramic tools

This study investigates tool wear characteristics of Cubic Boron Nitride (CBN) and ceramics (Al2O3 + TiC and Si 3N4) cutting tools, quality of machined surfaces (surface finish), dimensional error and cutting power when turning gray cast iron; grade G2 (class 40). A design of factorial experiment was performed at 3 levels of cutting speed, 2 levels of feed rate, 3 levels of depth of cut (DOC) and 3 different cutting tools. The effects of the different cutting conditions and tool materials used on the resulting surface finish of the workpiece, dimensional error, flank wear and cutting power are determined. The MANOVA, univariate ANOVA, Multiple Regression Analyses, and Simple Regression Analyses are used to analyze the data using the MINITAB package. The results show that all main effects and all two-way interactions are significant at the 95% confidence (alpha = 0.05) level. The study indicated that the performance of Si 3N4 and CBN as measured by the four dependent variables was superior to that of Al2O3 + TiC. The results of this study did not show a significant difference between the performance of CBN and Si3N4 on the resulting surface finish. The results did not show a significant difference between the performance of CBN and Si 3N4 on the resulting flank wear and cutting power. The study indicated that Si3N4 has the highest performance in providing the lowest dimensional error when compared to CBN and Al2O 3 + TiC.