Arbitrary Surface Flank Milling and Flank SAM in the Design and Manufacturing of Jet Engine Fan and Compressor Airfoils

A pragmatic and versatile airfoil design and fabrication system, named the Arbitrary Surface Flank Milling (ASFM) system, has been continuously developed and applied to the design and manufacturing of fan and axial compressor airfoils — in the form of integrally bladed rotors (IBR) and centrifugal impeller blades — for jet engines at Pratt & Whitney over the past 28 years. In a previous paper 18 years ago, we gave an account of the general concept and methodology of the system, illustrated with a number of actual production engine applications. We have since then greatly expanded the domain of applicability of the system to successfully handle blades of unusual geometric complexity. We have made strides in the area of design for flank mill-ability with conventional cutters, and cutters shaped according to blade geometry. Based on the same concept and software methodology, we have also successfully demonstrated the superior quality and cost effectiveness of Flank Super Abrasive Machining (Flank SAM) of blades in nickel-based alloy IBRs.