Effect of workpiece microstructure on tool wear behavior and surface quality during machining Inconel 718 alloy

Abstract

Since there are different performance requirements of superalloys in different service environments, the effect of the microstructure of Inconel 718 alloy on tool wear and surface quality was investigated in this study. Four types of microstructures were prepared through heat treatment experiments, and the differences in the microstructures of the workpiece were compared in detail. Subsequently, the cutting experiments were performed to expound on the influence of microstructure on cutting force and surface quality, and the comprehensive effect of microstructure on tool wear was revealed by studying the tool wear mechanism under SEM and through EDS. The results suggested that the hardness of the alloy was primarily affected by the number of strengthening phases and grain size, and the cutting force and hardness showed the same tendencies. The deformation grains and slip lines of the machined surface indicated the severity of the deformation and were largely affected by the coordination of deformation grain. In addition, the number of strengthening phases played an important role in thermal softening. Different tool wear behaviors were found in machining the above four microstructures. Compared with small grains, the deep hardening layer in the large grains led to notch wear.