Effect of High-Pressure Cooling and Cutting Speed on Residual Stresses Generated During Turning of an Advanced Wrought Nickel-Based Superalloy (AD730) using PCBN Tools

Abstract Ni-based superalloys components are utilised in some of the most hostile engineering environments. The exceptional high-temperature performance of these alloys presents significant challenges during manufacturing. Machining is a critical process, enabling the precise shaping of forgings into functional components. During material removal, plastic deformation of the workpiece material and friction generate substantial heat and high stresses, which can affect the integrity of both tool and workpiece. CBN (cubic boron nitride) tools are commonly employed for the finish turning of high-value Ni-based superalloy components. High-pressure cooling (HPC) is implemented to prevent premature tool failure by cooling the cutting tool and aiding chip breakage. In the study presented, the influence of HPC - and cutting speed on the resulting workpiece residual stresses were investigated during axial turning of an advanced wrought disk alloy (AD730). It was found that both HPC application and cutting speed influence residual stress depth profiles, which are known to enhance fatigue life and can therefore be optimised to improve in-service performance. Consequently, this research has significant implications for industries such as aerospace and power generation.