Microstructure of tungsten coatings effect on deuterium plasma-driven permeation through RAFM steel

• Published in: Nuclear materials and energy 2023-12, Vol.37, p.101557, Article 101557
• Main Authors: Yang, Kai, Xu, Yue, Tian, Xiao-Ping, Luo, Lai-Ma, Ni, Jun-Jie, Wu, Yu-Cheng
• Format: Article
• Language: English
• Subjects: Hydrogen isotope; Plasma-driven permeation; RAFM steel; Tungsten coating
• ISSN: 2352-1791; 2352-1791
• DOI: 10.1016/j.nme.2023.101557

•Tungsten coatings with different microstructures were prepared on CLF-1 by magnetron sputtering.•Deuterium transport parameters through tungsten coated CLF-1 were evaluated.•Effects of coating microstructure and incident ion energy on deuterium plasma driven permeation were discussed. Tungsten (W) coatings with different morphologies were deposited on CLF-1 steel by changing the sputtering time and discharge power using the magnetron sputtering method. Deuterium (D) plasma-driven permeation (PDP) experiments through W-coated CLF-1 were then carried out in the temperature range of 583–833 K. The obtained results showed that dense W coatings reduced steady-state permeation flux and prolonged the time of permeation flux reaching steady-state. Due to the existence of high-density intrinsic defects, D effective diffusivities of the coating are lower than that of bulk W. The increase of coating thickness reduced permeation flux. In addition, by changing the bias voltage and studying the influence of incident ion energy on D-PDP, it is found that the introduction of W coating affected the overall D transport by re-balancing the bulk diffusion and surface recombination processes. The thickness and microstructure of W coatings played a key role in determining the D steady-state permeation flux at varying temperatures.