A Study on Effects of Cutting Parameters on Surface Roughness in Dry Milling of Hastelloy C276

Hastelloy C276 is a nickel-based superalloy widely used in aerospace, chemical processing, and energy industries due to its excellent corrosion resistance and high mechanical strength. However, its low thermal conductivity and strong work-hardening behavior make the alloy difficult to machine, leading to poor surface quality. This study investigates the effects of cutting parameters on surface roughness (Ra) during dry milling of Hastelloy C276. Milling experiments were carried out on a Mazak Smart 530C vertical machining center using Titan-coated carbide inserts. A Box–Behnken response surface methodology was employed to design the experiments and analyze the influence of cutting speed (V), feed rate (f), and depth of cut (t) on machining performance. The developed regression models showed good agreement with the experimental data, with coefficients of determination of 93.86% for surface roughness. The results showed that feed rate was the most influential factor affecting surface roughness. Single-objective optimization determined the optimal set of parameters including V = 42 m/min, f = 0.08 mm/tooth and t = 0.2 mm for the minimum surface roughness value Ra = 0.1884 µm. The findings provide useful guidelines for improving machining performance of Hastelloy C276 in dry milling conditions.