The modified surface properties and fatigue life of Incoloy A286 face-milled at different cutting parameters

Abstract

Incoloy A286 alloy is an iron-base superalloy that widely used in gas turbine jet engines and other similar applications, and the high reliability demand of such applications drew significant attention to the machining induced surface integrity and fatigue life. In this work, the Incoloy A286 was face-milled at different cutting parameters, and the surface properties and fatigue life of the modified surface were measured and analysed. It is found that the cutting parameters can modify the surface integrity and mechanical properties significantly, and further obviously influence the fatigue life of the workpiece. The modified fatigue life under different cutting parameters was mainly determined by the roughness and mechanical properties, including the yield strength and fracture toughness, rather than the residual stresses, because of the severe stress relaxation. The surface yield strength had strong positive correlation with the work hardening, while the surface fracture toughness (KJC) was related to the work hardening formation mechanism and grain refinement. The optimal cutting parameters were recommended according to the surface integrity and fatigue life measurement results at last.