One-step preparation of α-Al2O3/SiO2 composite tritium permeation barrier via slurry spin coating method and performance investigation

Abstract

In the fusion reactor, a-Al2O3 and its composite coatings have became the preferred material for tritium permeation barriers. The slurry spin coating method in this study is used to prepare α-Al2O3/SiO2 composite coating for one-step at the temperature of 600 °C, 700 °C and 800 °C. The effect of heat treatment temperature on the composite coating's microstructure and adhesion strength is investigated. When the coating prepared temperature is 600 °C, the thermal shock resistance and hydrogen permeation resistance are also studied. The findings demonstrate that as the heat treatment temperature rises, defects such as holes and cracks appear. The surface of the composite coating is continuous and compact when the preparation temperature is 600 °C, and the adhesion strength is 88.7 N. Thermal shock tests demonstrate that the 600 °C-α-Al2O3/SiO2 composite coating is still dense and is bonded well to the substrate after 50 times thermal shocks at 500 °C. The hydrogen resistance capability indicate that the 600 °C-α-Al2O3/SiO2 composite is 4.6 times greater than the substrate.