Tool wear mechanisms and multi-response optimization of tool life and volume of material removed in turning of N-155 iron-nickel-base superalloy using RSM

In the present work, the effects of cutting parameters on tool life of PVD TiAlN-coated carbide tools and volume of workpiece material removed during the machining of the N-155 iron-nickel-base superalloy are evaluated. Cutting speed and feed rate each at five levels were selected as cutting variables. The relationships between machining parameters and output variables were modeled by using response surface methodology (RSM). Analysis of variance (ANOVA) was performed to check the adequacy of the mathematical model and its respective variables. The results showed a good agreement between the measured tool life and volume of material removed and predicted values obtained by developed models. In addition, the cutting tool inserts were examined under scanning electron microscope (SEM) and wear mechanisms were analyzed at various cutting speeds. It was observed that adhesion was the most dominant tool failure mode. Finally, the multiple response optimization of tool life and volume of material removed for achieving maximum productivity was carried out using the desirability function approach.