Research on the Shear Angle Theory Based on the Internal Friction in High-Speed Cutting of High-Entropy Alloy FeCoNiCrAl

High-entropy alloys are typically emerging and difficult-to-cut multi-element alloys with high hardness, high strength and good fatigue performance and are considered to have good application prospects, but their processability remains to be studied. High-speed cutting, as a mature rough processing for hard-to-machine alloys, is characterized by serrated chips and is attributed to the shear, compression and internal friction within the primary deformation zone. However, in conventional shear angle theories, the effect of internal friction is often ignored, resulting in unstable accuracy when these theories are applied to high-speed cutting. Improving the existing shear angle theories will elaborate the balance between deformation and friction in high-speed cutting more clearly, which has certain instructiveness to engineering applications. Thus, an improved shear angle model considering internal friction is combined herein with orthogonal high-speed cutting experiments on the high-entropy alloy FeCoNiCrAl to obtain the cutting performance of the material. After modification, the scope of application of shear angle theories was expanded from low-speed cutting to high-speed cutting. The internal friction angle is mainly affected by the cutting speed as well as the thermal conductivity of materials.