Can higher cutting speeds and temperatures improve the microstructural surface integrity of advanced Ni-base superalloys?

Abstract

Future Ni-base superalloys are designed to deliver outstanding mechanical behaviour at high temperatures, which may translate in significant machining challenges. In this work, a paradigm is presented by which is proven how machining of these materials could benefit from increased cutting speeds and temperatures provided that they are able to promote shear localisation and thermal softening in the chip deformation zones, whilst retaining high-temperature strength within the machined surface. In this way, thermal control of chip formation leads to both lower cutting forces and energies, as well as enhanced surface integrity with lower levels of microstructural reconfiguration.