PREDICTING THE OPTIMAL PARAMETERS BY MULTI-OBJECTIVE DECISION MAKING WHILE MACHINING AN Al6061 ALLOY USING CBN INSERTS WITH DIFFERENT CUTTING-EDGE GEOMETRIES

The present work aims to investigate the effect of cutting-tool edge geometry on cutting force and surface finish while machining an Al6061 alloy under different conditions. A series of experiments was performed with a custom-fabricated cutting insert of a chamfered edge to observe the effect of feed rate and depth of cut on the cutting forces and surface finish. The results showed that varying the cutting-edge geometry has a significant effect on controlling the cutting forces. Also, as the feed and depth of cut were reduced (at high cutting speeds), the surface roughness was observed to reduce with the geometry effect. Furthermore, in the present work validation of the experimental results were also performed based on a multi-criteria decision-making method called Grey Relational Analysis (GRA). The weighted GRA predicted the optimal combination of machining parameters for two different cutting-tool inserts. Finally, the obtained optimal results were compared with the predicted and experimental values in terms of weighted GRG. The result shows that there was no significant improvement while using the standard cutting tool, whereas a net improvement of 16.9 % was observed while using the chamfered cutting tool for machining the Al 6061 alloy.