ALUMINA, CALCIA, BARIA SEALING COMPOSITION AND ARTICLE OF MANUFACTURE

摘要

An improved sealing composition for use between alumina ceramic parts, or between alumina ceramic and refractory metal, is centered on 47 weight percent Al2O3, 37 weight percent CaO and 16 weight percent BaO. The composition has a lower liquidus temperature (1325.degree.C) than an otherwise similar one previously used which included 5% MgO, and its thermal expansion coefficient is less affected by dissolved Al203. As a result, a closer thermal match with alumina ceramic can be maintained during seal processing and the rejection rate is reduced.