Flat-end mill machining analysis of processed CrMnFeCoNi high-entropy alloys

High-entropy alloys are emerging materials and are widely studied at the synthesis and characterization levels. Their machinability study and product realization are still at a nascent stage. Conventional machining operations are necessary to ensure part assembly and surface quality. Hence, end-mill machining is carried out to check the machinability of the most ductile equiatomic and non-equiatomic CrMnFeCoNi high-entropy alloy (HEA) with a green manufacturing concept. Theoretical and experimental analyses examined the effect of percent composition of an element in a high-entropy alloy and machining parameters (spindle speed, depth of cut and feed per tooth) on the cutting forces, chip morphology, machined surface topography, surface micro-hardness and tool wear mechanism. Kistler dynamometer installed in CNC vertical milling machine is used with AlTiN-coated tungsten carbide tool to record the cutting forces and moments. The microstructure anisotropy induced by low vacuum induction melting of varying compositions of elements in high-entropy alloys influenced the machining results. Feed force values were higher for the non-equiatomic HEA sample than for the equiatomic CrMnFeCoNi HEA. SEM and EDS mapping has revealed microhole and microcrack surfaces after machining. Equiatomic CrMnFeCoNi HEA has shown the highest microhardness of 984 Hv than the non-equiatomic HEA sample.