Thermal properties of glass-ceramic bonded thermal barrier coating system
(Bio-ceramics and Coating Division, CSIR–Central Glass and Ceramic Research Institute, Kolkata 700032, India)
Abstract: The thermal properties of a thermal barrier coating (TBC) system comprised of BaO–MgO–SiO2 based glass-ceramic bond coating, 8% (mass fraction) yttria stabilized zirconia (8YSZ) top coating and nimonic alloy substrate were evaluated. The thermal diffusivity and thermal conductivity of the TBC coated substrate were lower than those of bare substrate and glass-ceramic coated substrate under identical conditions. The specific heat capacity, thermal diffusivity and thermal conductivity of the TBC coated substrate increase with the increase of the temperature. Further, it is observed that the thermal conductivity of the TBC system decreases with the increase in the top coating thickness.
Key words: glass-ceramic coating; thermal barrier coating; thermal properties; yttria stabilized zirconia