Characterisation of the grinding process of airfoil-shaped geometries using superabrasive machining

Abstract Electroplated cBN tools are widely used in superabrasive machining (SAM) processes for grinding nickel-based alloys, which play a crucial role in the aerospace industry. These tools are commonly employed for machining airfoils and vanes, but their application in manufacturing of integrated blade rotors (IBRs) airfoils remains limited. This study presents a methodology for evaluating the performance of SAM when machining geometrical surfaces analogous to IBR airfoils. Test parts made from Inconel 718 were machined by cBN electroplated wheel with two different grit sizes, 46 µm and 76 µm, and two different concentrations to analyse the influence of key process parameters, including cutting speed, feed rate, and grinding wheel characteristics, on specific energy, cutting forces, wheel wear, and part surface roughness and metallurgical integrity. The results reveal that at higher levels of aggressiveness, 76-µm grits lead to up to 15% lower specific energies, whereas this trend reverses as aggressiveness decreases. The cutting force ratio remains more stable at higher aggressiveness levels, showing no significant variation across different grit sizes or concentrations under the studied conditions. Surface roughness is primarily influenced by grit size, while wear induced by cutting conditions playing a secondary role. No significant defects were found on the produced surfaces.