EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The equiatomic hexagonal closest-packed (hcp) high entropy alloy (HEA) YGdTbDyHo consists of rare earth elements with very similar chemical properties. Therefore, it is a suitable candidate for the investigation of the Gibbs paradox and of a possible entropy effect on mechanical behavior of alloys. To evaluate the influence of the configurational entropy, different medium entropy alloys (MEA), low entropy alloys (LEA) and pure constituent elements are considered as well.
All samples were prepared via suction casting in an electric arc furnace. Different manufacturing influences on the suction casting of YGdTbDyHo are discussed. The microstructure and chemical composition of YGdTbDyHo is analyzed via Scanning electron microscopy (SEM), Electron backscatter diffraction (EBSD) and X-ray fluorescence analysis (µ-XRF). To evaluate the strength and ductility of the materials, tensile tests are conducted. Additionally, the Vickers hardness HV 0,3 of all materials is determined.
The results show no direct correlation between Vickers hardness or tensile strength and the configurational entropy of the tested materials. This work contributes to the understanding of mechanical properties and the influence of configurational entropy on the hcp HEA YGdTbDyHo.