Resistance Tritium Coated With The Wet Chemical Method Of Oxide Nanopowder Preparation And Research

Tritium is the main fuel of controllable thermal nuclear reactors and thermonuclear weapons with a strong penetration and diffusion in most of the metal materials. Tritium penetration will cause a range of issues. After years of research, it has been widely recognized that the tritium barrier on the stainless steel surface is the most feasible way to solve the problem of tritium permeation. The oxide coating is currently one of the most important functional coatings, and attracts a wide attention. Nanotechnology can improve many aspects of coating performance. Therefore, in this paper we studied oxide nano-materials which could be used in tritium barrier. We focused on the influence of preparation processing on morphology, crystal structure of nanoparticles. Finally we prepared tritium barrier coatings using the nanoparticles we manufactured, and tested their performance.YSZ nano-powders were prepared by sol-gel and sol-hydrothermal methods, which were both of simple wet chemical methods. Detailed investigations were focused on the influence of the hydrothermal conditions and the concentration of the mineralizer on the YSZ nano-particle size, morphology and coating microstructure. The results showed that the YSZ nano-particles were the best when heated at 250oC for 48h with 10 mol/L concentration of the mineralizer. Study was also done on the sintering temperature about sol-gel. The best YSZ nano-particles were prepared when sintered at 500oC. The particle size was around 50 nm and suitable for the preparation of coating.The Er2O3 nano-powders were prepared by sol-hydrothermal and chemical precipitation methods, which were also both of simple wet chemical methods. The impact of hydrothermal temperature, hydrothermal time and sintering on powder were investigated in hydrothermal method. The results showed that Er2O3 powders with the aspect ratio at 12:1-15:1 could be obtained when it was heated at 140oC for 16h. Well crystallized Er2O3 were obtained after the hydrothermal products baked at 700oC. With chemical precipitation methods, the particle size of Er2O3 nano-powders was around hundreds of nanometers with good crystallization and shape. The optimum sintering temperature for Er2O3 crystallization was 700oC. High-quality YSZ and Er2O3 tritium barriers were prepared successfully on non-planar substrates by simple two-step methods using the nano-particle manufactured. We tested both of them to verify their performance against tritium penetration. The results showed that YSZ coating was weak to prevent the tritium permeation, while Er2O3 coating exhibited good tritium resistance property but the performance was still lower than advanced international level.