Experimental optimization of cutting conditions to improve surface roughness of aeronautic parts made of Fe-Ni alloys

Fe-Ni alloys present excellent heat resistance properties while preserving their rigidity, strength, toughness, and dimensional stability at high temperatures. As a result, they are widely used in manufacturing aerospace or aeronautic parts where the operating temperature is very close to their melting temperature. Supra50 (named in the Unified Numbering System UNS as K94800) is a Fe-Ni alloy currently used in space and aviation industries, which confirmed its efficiency. However, improving the surface roughness of this high-precision part is challenging to overcome in manufacturing. The main objective of this study is to carry out an experiment based on a factorial plan and aims to predict the surface roughness of Supra50 parts as a function of cutting parameters in a milling process. Results show that the best combination of cutting parameters, giving the best surface roughness, is obtained at the lowest value of feed per tooth. Results also show that cutting speed and radial depth have little effect on roughness quality.