摘要 |
For sealing metal annular elements on to a cylindrical ceramic member, e.g. a ceramic electrolyte tube in a sodium-sulphur cell without causing excessive hoop stress in the ceramic, the ceramic tube is formed with tapered inner and outer surfaces at one end, correspondingly tapered inner and outer annular elements are put over these surfaces with a soft metal, e.g. aluminium interface layer, the inner and outer annular elements having coefficients of thermal expansion respectively less than and greater than that of the ceramic, the assembly is then heated and the annular elements forced in the axial direction onto the ceramic whereby the ceramic material, on cooling, is tightly secured between the annular members. |