Diffusion and Absorption of Hydrogen in Liquid-Quenched and Annealed Ni₈₁P₉₁Alloy

Abstract

Transport and absorption of hydrogen were studied in the Nia1 P79 alloy in the as-quenched amorphous state and after annealing for 1 h at temperatures up to 873°K. The diffusivity and the amount of diffusible and trapped hydrogen were determined from electrochemical permeation measurements performed at 298°K. After annealing below the crystallization temperature (Tc = 560°K), the hydrogen diffusivity and absorption rose by up to about twice, whereas at higher temperatures (formation of the Ni and N13P phases) they drastically decreased, with a drop in diffusivity being almost three orders of magnitude. Below Tom, the ratio of trapped hydrogen to total absorbed hydrogen almost did not change with the annealing temperature, being about 0.75. The rise in the hydrogen diffusivity and absorption below T c may result from local ordering of atoms; it demonstrates that the behavior of hydrogen may be a sensitive measure of structural relaxation in the amorphous alloy.KEY WORDS: amorphous and annealed Ni81 P79 alloy, hydrogen absorption and diffusion.

Anodic Etching of Amorphous Ni81P19 Alloy in Hot Concentrated Chloride Solution for Enhanced Hydrogen Evolution in Alkaline Water Electrolysis

“…The study was carried out mainly on the as‐received (amorphous) alloys, and to a lesser extent on annealed (crystalline) samples. Annealing was performed in a vacuum above the crystallization temperatures (290 °C for NiP [57] ). NiP was annealed at 320 °C for 30 min, and NiCrFeBSi was annealed at 420 °C for 15 min.…”

“…[41] Good electroactivity for water splitting is also exhibited by amorphous alloys. [45][46][47][48][49][50][51][52][53][54][55][56][57] Examined alloys contained several elements, basically transition metals Fe, Ni or Co, and Mo, P, B or Si. The alloys were activated by etching and straining which caused dealloying or induced microcracks.…”

“…Good electroactivity for water splitting is also exhibited by amorphous alloys [45–57] . Examined alloys contained several elements, basically transition metals Fe, Ni or Co, and Mo, P, B or Si.…”