Effect of Cr_(2)O_(3) nanosheet insertion on the deuterium permeation behavior of a Cr-Zr-O coating

In this study,a Cr_(2)O_(3) nanosheet(Cr_(2)O_(3) NS)inserted Cr-Zr-O coating was developed as a hydrogen isotope permeation barrier.The Cr_(2)O_(3) NSs,fabricated by rapid heat treatment,were amorphous with a thickness of only several nanometers.These Cr_(2)O_(3) NSs were then incorporated into a Cr-Zr-O multi-metal oxide composite coating via a dip-coating method to form a coating.The effect of the Cr_(2)O_(3) NS concentration on the morphology,microstructure and deuterium permeation resistance of the coating was studied.With the addition of 1.0 g 1^(-1)Cr_(2)O_(3) NSs,compared with the Cr-Zr-O coating without NSs,the permeation reduction factor of the resultant coating was enhanced from 249℃to 575℃ at 500℃.The coating,with a thickness of nearly 193 nm,achieved a comparable deuterium resistance that was above two orders of magnitude higher than the steel substrate.The results show that ceramic NSs can serve as effective fillers for enhancing the coating performance when functioning as a hydrogen isotope barrier.

Layer-structured Cr/Cr_(x)N coating via electroplating-based nitridation achieving high deuterium resistance as the hydrogen permeation barrier

Hydrogen isotope permeation through structural materials is a key issue for developing nuclear fusion energy,which will cause fuel loss and radioactive pollution.Developing ceramic coatings with high thermal shock and hydrogen resistance is an effective strategy to solve this issue.In this work,a layer-structured Cr/Cr_(x)N coating was successfully fabricated by a facile electroplatingbased nitridation technique,which is easy,facile,and applicable to coating complex-shaped substrates.The Cr/Cr_(x)N coating,composed of a bottom Fe/Cr interdiffusion zone,a middle Cr layer,and a top Cr_(x)N layer,exhibits high bonding strength,high anti-thermal-shock ability,and high deuterium permeation resistance.Its bonding strength achieves 43.6 MPa.The Cr/Cr_(x)N coating remains intact even after suffering 300 thermal shock cycles under a 600℃–water condition.Through optimizing the nitridation temperature,the Cr/Cr_(x)N coating achieves a deuterium permeation reduction factor(PRF)as high as 3599 at 500℃.Considering its scalable fabrication technique and considerable properties,the developed Cr/Cr_(x)N coating may serve as a novel high-performance hydrogen permeation barrier in various fields.