Thermal Cycle Stability of Sealing Glass for 8YSZ Coated Cr-Containing Metal Interconnect

An 8 mol. % yttria stabilized zirconia (8YSZ) coating has been prepared on a Cr-containing stainless steel interconnect (SS410) to improve the chemical compatibility of a BaO-B2O3-SiO2 sealing glass with the SS410. Three different methods as, grinding the 8YSZ coating prior to the sealing (fixture A), putting an interlayer glass on the 8YSZ coating prior to the sealing (fixture B), and exerting an external compressive force of similar to 10.28 kPa during the sealing (fixture C), have been used to improve the thermal cycle stability of the sealing glass. The fixture A (using the grinding method) and the fixture B (using the interlayer method) both show poor thermal cycle stability. For the fixture C, the external compressive force is found to help the self-healing of the sealing glass. Due to the good chemical compatibility of the sealing glass with the 8YSZ coating, the sealing glass of the fixture C exhibits super long-term thermal cycle stability. The leak rates of the sealing glass of the fixture C show nearly no increase up to 280 thermal cycles, after which the leak rates increase slowly with the thermal cycles and the leak rate is still less than the Solid Energy Convergence Alliance (SECA) limit at the 626th thermal cycle.