Hydrogenated boron-silica alloy films having unexpected properties permitting in one embodiment the bonding together of metal and ceramic substrates by coating the surfaces to be bonded with the film mating the surfaces and heat treating the mated surfaces to expell hydrogen therefrom and to react to resulting boron-silicon alloy film with the substrates to form a liquid reaction product which forms a surface bond with the substrates or is at least partially absorbed in the substrates. In another embodiment, at least one surface of an intermetallic compound formed from elements selected from groups III and V of the periodic table is sealed against structural degradation by forming on the surface a solid boron-silicon-hydrogen alloy film. In still another embodiment, metal and organic resin substrates are protected against attack by water vapor, dissociated oxygen and molecular oxygen by forming a solid boron-silicon-hydrogen alloy film on the substrates. The metal substrates are further protected against deterioration by the effects of the recombination of dissociated oxygen and nitrogen by converting the solid boron-silicon-hydrogen alloy film to solid boron-silicon oxide film.
A Si--SiC ceramic layer is bonded to a non-porous SiC substrate with the Si etched from the layer to form a relatively porous surface on the otherwise non-porous high strength SiC substrate. A quartz layer is softened by heating and forced into the pores of the porous layer to form a mechanical bond to the SiC substrate. A refractory metal layer is bonded to the quartz layer to complete the joint. A refractory metal support component is then bonded to the refractory layer whereby the quartz serves as a high strength, high temperature reaction barrier between the metal of the refractory layer and the silicon of the SiC substrate.
Methods of forming oxide layers on silicon carbide layers are disclosed, including placing a silicon carbide layer in a chamber such as an oxidation furnace tube that is substantially free of metallic impurities, heating an atmosphere of the chamber to a temperature of about 500 .degree. C. to about 1300 .degree. C., introducing atomic oxygen in the chamber, and flowing the atomic oxygen over a surface of the silicon carbide layer to thereby form an oxide layer on the silicon carbide layer. In some embodiments, introducing atomic includes oxygen providing a source oxide in the chamber and flowing a mixture of nitrogen and oxygen gas over the source oxide. The source oxide may comprise aluminum oxide or another oxide such as manganese oxide. Some methods include forming an oxide layer on a silicon carbide layer and annealing the oxide layer in an atmosphere including atomic oxygen.
