CoCrFeNiSi high entropy alloy: Synthesis, structural and radiation shielding properties

Abstract

High entropy alloys (HEAs) have emerged as a distinct class of alloys with unique design strategies, different from traditional alloys. These alloys hold great promise for diverse applications, and the investigation of their nuclear radiation shielding properties has become an important and emerging area of research. In this experimental study, an equimolar CoCrFeNiSi HEA was prepared using the ball milling method. The focus was on characterizing the crystalline structure, morphological features, and radiation shielding properties of the synthesized HEA. X-ray diffraction analysis revealed that the HEA exhibited a face-centered cubic (FCC) phase structure. The crystallite size was significantly reduced from 23.63 nm to 3.22 nm, indicating the refinement of the microstructure. The homogeneity of the alloy was confirmed through scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), which showed that the five elements were uniformly distributed within the powder alloy. To evaluate the radiation shielding properties, linear attenuation coefficients (LAC) of the CoCrFeNiSi HEA powder were measured using a 662 keV gamma source and a NaI(Tl) detector system (ORTEC® 905–4). The experimental LAC values were determined to be 0.2140 ± 0.01 cm⁻1. Theoretical calculations using MCNP6.2 and XCOM code were also performed and showed good agreement with the experimental results. Comparing the CoCrFeNiSi HEA with common shield materials such as thin films, glass systems, and some composites, it was found that the HEA outperformed them in terms of radiation shielding effectiveness. This demonstrates the potential of the CoCrFeNiSi HEA as an advanced alternative to conventional shielding materials, with potential applications in various fields.