Consideration of Alumina Coating Fabricated by Sol-gel Method as MHD Coating against PbLi

Development of effective electrical magnetohydrodynamic (MHD) coating insulating induced current path is one of key fusion technologies for fusion blanket research and development. Electrical insulation coating is extremely important for lead lithium (PbLi) MHD thermofluid study from pointview of secure electric insulating wall condition. The alumina (Al2O3) coatings fabricated by a sol-gel method have never studied as electrical insulation coating against PbLi as a working fluid. The present paper discusses the feasibility of the Al2O3 coating by the sol-gel method as an electrical insulation coating for PbLi MHD flows. It is examined the electrical insulation durability of the Al2O3 coating by the sol-gel method with molten PbLi exposed. The Al2O3 coatings worked as electrical insulation coating for 170 hours with PbLi temperature at 300 C in this study. However, the Al2O3 coating cured up to around 370 C seemed to have a threshold for the electric insulation break above 400 C. Nevertheless, the Al2O3 coating fabricated by the sol-gel method will be a potential electric insulation coating for PbLi flow under the MHD condition with the operation time and the temperature limitation.