Modelling cutting force for turning AISI 304 stainless steel with PVD-AlTiN coated, PVD-AlTiN coated-microblasted, and MTCVD-TiCN/Al2O3 coated tools

Abstract

ABSTRACT Stainless steel is challenging to machine, and to avoid any negative consequences, it is essential to comprehend the cutting forces. With this view, this study has developed a cutting force model for turning AISI 304 stainless steel with the most preferred PVD-AlTiN coated (C-type), PVD-AlTiN coated-microblasted (CMB), and MTCVD-TiCN/Al2O3 coated carbide tools (MTCVD). Empirical models are developed to predict the chip thickness ratio, the normal shear angle, and sharp tool cutting forces. Studies showed the reduction in forces with the cutting speed for C-type, CMB, and MTCVD tools was 12–20%, 11–32%, and 6–29%, respectively. However, the corresponding increases with the feed and depth of cut were 60–134%, 125–146%, and 97–178%; 76–186%, 55–384%, and 14–274%, respectively. Additionally, a cutting force model considering the tool wear effect is developed for MTCVD tools, which exhibited lower tool wear compared to other tools. The study accurately predicted sharp tool and worn tool cutting forces, showing good quantitative agreement with experimental results with an average error of less than 10%. However, some discrepancies were observed beyond the flank wear length of 0.2 mm. It was due to the chipping of the coating layers and the pitting of the substrate from the nose area.