Abstract:
Structural members are joined together by a high temperature, electrically conductive hermetic seal comprising an outer layer of platinum having intimate contact with, and good adhesion to, one of the structural members to be joined together, an inner layer of platinum having intimate contact with, and good adhesion to, the other structural member to be joined together, a layer of a metal whose initial composition before formation of the seal is gold or 18 percent by weight of nickel and the remainder gold centrally disposed between, joined to, and alloyed with the inner and outer layers of platinum by respective intermediated metal layers comprising gold.
Abstract:
A single piece open ended polycrystalline oxide body having a generally tubular configuration with a smaller internal diameter at its ends than the internal diameter adjacent its mid-portion. The body is produced by isostatic pressing of prepared small uniform spherical agglomerates of the oxide powder in a urethane outer mold carrying a preshaped low melting point metal mandrel. The mandrel is removed after pressing by melting and the remaining oxide body is then sintered in a hydrogen atmosphere at high temperature to produce the polycrystalline structure.