Thermal Cycle Reliability of Glass/Ceramic Composite Gas Sealing Materials

We have developed glass/ceramic composite seals composed of glass precursors (NS particles) and ceramic precursors (S particles). The composite seals exhibited low gas permeability at room temperature −650°C, irrespective of the fusion profiles. However, short‐term fusion led to the formation of pores in the seals and the pores in the seals depressed the thermal cycle durability. As for the NS/S composite ratios, the addition of S particles obviously improved the thermal cycle durability, but excess addition will bring about delamination at the seal/substrate interface. Appropriate NS/S ratios as well as an adequate fusion profile would result in composite seals with high strength and adhesion.