Xaba Morena S
Advanced Materials Division, Mintek, Private Bag X 3015, Randburg, 2125, South Africa.
Heliyon. 2024 Jun 8;10(12):e32715. doi: 10.1016/j.heliyon.2024.e32715. eCollection 2024 Jun 30.
This review paper covers an analysis of the empirical calculations, additive manufacturing (AM) and hydrogen storage of refractory high-entropy alloys undertaken to determine the structural compositions, particularly focusing on their applicability in research and experimental settings. The inventors of multi-component high-entropy alloys (HEAs) calculated that trillions of materials could be manufactured from elements in the periodic table, estimating a vast number, N = 10^100, using Stirling's approximation. The significant contribution of semi-empirical parameters such as Gibbs free energy , enthalpy of mixing , entropy of mixing , atomic size difference , valence electron concentration , and electronegativity difference are to predict BCC and/or FCC phases in HEAs. Additive manufacturing facilitates the determination of refractory HEAs systems with the most stable solid-solution and single-phase, and their subsequent hydrogen storage capabilities. Hydride materials, especially those from HEAs manufactured by AM as bulk and solid materials, have great potential for H storage, with storage capacities that can be as high as 1.81 wt% of H adsorbed for a ZrTiVCrFeNi system. Furthermore, laser metal deposition (LMD) is the most commonly employed technique for fabricating refractory high entropy alloys, surpassing other methods in usage, thus making it particularly suitable for H storage.
这篇综述论文涵盖了对难熔高熵合金的经验计算、增材制造（AM）和储氢的分析，旨在确定其结构组成，尤其关注它们在研究和实验环境中的适用性。多组分高熵合金（HEAs）的发明者计算得出，利用元素周期表中的元素可以制造数万亿种材料，使用斯特林近似法估计数量巨大，N = 10^100。吉布斯自由能、混合焓、混合熵、原子尺寸差、价电子浓度和电负性差等半经验参数的重要贡献在于预测高熵合金中的体心立方（BCC）和/或面心立方（FCC）相。增材制造有助于确定具有最稳定固溶体和单相的难熔高熵合金体系及其随后的储氢能力。氢化物材料，特别是通过增材制造制成的块状和固态高熵合金氢化物材料，具有很大的储氢潜力，对于ZrTiVCrFeNi体系，储氢容量可高达吸附氢的1.81 wt%。此外，激光金属沉积（LMD）是制造难熔高熵合金最常用的技术，在使用频率上超过其他方法，因此使其特别适合储氢。
