A Review: Literature Summary on the Relationship Between Cutting Parameters and Machinability in Turning Operations

This study presents a comprehensive evaluation of machinability in turning operations by reviewing and synthesizing the literature based on the parameters of cutting forces, tool wear, and surface roughness. Previous studies clearly present the significance of cutting parameters. While an increase in speed mainly reduces the forces and roughness, increases in feed and depth tend to increase cutting forces, temperature, and wear by enlarging the contact area. Tool wear directly affects the surface integrity and process stability through flank/crater wear and BUE formation. In particular, austenitic stainless steels, titanium and nickel-based superalloys, and particle-reinforced composites are sensitive to the cutting mechanism, tool-material interaction, and speed. Environmentally sustainable cooling-lubrication strategies (MQL, plant-based oils, cryogenic/CO₂-based solutions) reduce wear by reducing friction and temperature, improving the surface quality. In the case of ultrasonic turning, similar benefits are provided by reducing instantaneous contact and average forces. In the examined studies, dynamometers, scanning electron microscopes, surface roughness measurement instruments, and various software were used. Additionally, optimum parameter windows were reported based on Taguchi/ANOVA/RSM methods. Consequently, the combination of appropriate parameter selection and environmentally friendly cooling and lubrication and/or auxiliary processes extends tool life, improves surface integrity, and increases energy and cost efficiency. This approach offers a repeatable and industrially applicable roadmap, even for materials that are difficult to machine.