Contact angle measurement of molten lead–lithium on silicon carbide surfaces

Measurements of the contact angles at the different temperatures of a molten lead–lithium eutectic alloy (PbLi) droplet on a silicon carbide (SiC) wall are needed for the research and development both of a magnetic confinement fusion (MCF) and an inertia confinement fusion (ICF) blankets. PbLi coolant/breeder flows in the coolant channel, which is made of the SiC walls, and will experience a flow slip at the wall, called as a magnetohydrodynamic (MHD) slip flow. The ICF blanket adopts a molten PbLi film flow along the first wall made of SiC. The PbLi contact angle database is necessary as the thermal property for numerically predicting the behavior of the flowing molten PbLi film. This study attempts the measurement of the contact angles between the molten PbLi and the various SiC surfaces. For example, in order to examine the initial PbLi wettability, we measured the contact angles of a chemical vapor deposition (CVD) SiC, a nano-infiltration and transient eutectic-phase (NITE) SiC/SiC composites, and a NITE SiC in an inert atmosphere. We obtained the contact angle database of the molten PbLi, varying the temperature of PbLi from 250 to 400 °C, on a surface-polished as well as an unpolished SiC.