Speaker
Carlota Soto
(Departament of Materials)
Description
Flow Channel Inserts (FCI) are key elements in a Dual Coolant Lead Lithium blanket concept for DEMO, since they provide the required thermal and electrical insulation between the He cooled structural steel and the hot liquid Pb-15.7Li flowing at around 700°C, and minimize MHD pressure loss. FCIs must be inert in contact with Pb-15.7Li and show low tritium permeability. In addition, FCIs have to exhibit sufficient mechanical strength to withstand thermal gradients during operation.
SiC fulfils the operational requirements for FCIs. Besides, porous SiC is an attractive candidate to obtain a thermally- and electrically- low conducting structure. To prevent tritium permeation and corrosion by Pb-15.7Li a dense SiC coating shall be applied on the porous SiC.
In this work a SiC-based sandwich material consisting of a porous SiC core covered by a dense CVD-SiC layer is proposed. The production method of the porous SiC consists in combining the particle size of the starting mixture of SiC powder and a carbonaceous sacrificial phase (which is removed after sintering by oxidation), in such a way that a honeycomb microstructure –mechanically more resistant- is achieved. The porosity of this tailored microstructure results in low enough thermal conductivity for sufficient thermal isolation through a core thickness of 5 mm, as determined by thermo-mechanical analysis. This analysis provides also the optimum thickness of the dense CVD-SiC layer for minimizing thermal stresses. In this paper a study of the microstructure, thermal and electrical conductivities and flexural strength of the sandwich material with a dense CVD-SiC coating of 200 µm is presented. In order to ascertain whether this dense layer thickness is enough to withstand the contact with the hot PbLi without corrosion damage, laboratory tests have been performed in static PbLi at 700-800°C during 1000 h. The results of these tests are presented.
Co-authors
Alejandro Morono
(National Fusion Laboratory, CIEMAT, Avenida Complutense 40, E-28040 Madrid, Spain)
Carlota Soto
(Departament of Materials, CEIT-IK4, Paseo Manuel Ladrizábal 15, E-20018 San Sebastián, Spain;Tecnun, University of Navarra, Paseo de Manuel Lardizábal 13, E-20018 San Sebastian, Spain)
Carmen Garcia-Rosales
(Departament of Materials, CEIT-IK4, Paseo Manuel Ladrizábal 15, E-20018 San Sebastián, Spain;Tecnun, University of Navarra, Paseo de Manuel Lardizábal 13, E-20018 San Sebastian, Spain)
Ernests Platacis
(Institute of Solid State Physics, University of Latvia, 32 Miera iela, Salaspils, Latvia)
Faina Muktepavela
(Institute of Solid State Physics, University of Latvia, 32 Miera iela, Salaspils, Latvia)
Jon Echeberria
(Departament of Materials, CEIT-IK4, Paseo Manuel Ladrizábal 15, E-20018 San Sebastián, Spain)
Jose Manuel Martinez-Esnaola
(Departament of Materials, CEIT-IK4, Paseo Manuel Ladrizábal 15, E-20018 San Sebastián, Spain;Tecnun, University of Navarra, Paseo de Manuel Lardizábal 13, E-20018 San Sebastian, Spain)
Marta Malo
(National Fusion Laboratory, CIEMAT, Avenida Complutense 40, E-28040 Madrid, Spain)
Teresa Hernandez
(National Fusion Laboratory, CIEMAT, Avenida Complutense 40, E-28040 Madrid, Spain)
