Accession Number : AD0269513

Title :   INVESTIGATION FOR THE DEVELOPMENT OF CERAMIC BODIES FOR ELECTRON TUBES

Corporate Author : GENERAL ELECTRIC CO SCHENECTADY N Y

Personal Author(s) : WISELY,H.R.

Report Date : DEC 1961

Pagination or Media Count : 1

Abstract : Efforts to produce a nonabsorbent microcrystalline quartz body by high-temperature firing of Ca-doped SiO2 that had been precalcined to develop the quartz phase failed. Compositions were formulated in which Ca2SiO4 was the principal phase. Means of doping the compositions to prevent body disintegration, caused by the beta to gamma inversion on cooling, were studied. The presence of sufficient MgO prevented the test discs from dusting and seemed to preserve beta-Ca2SiO4 to room temperature. Similar stabilization was obtained by the introduction of approximately 1 wt-% B2O3, or by the formation of a solid solution having a mole ratio of 1 Ca3(PO4)2:15 Ca2SiO4. The 1 Ba2SiO4:15 Ca2SiO4 composition was not stabilized, but the 1 Ba2SiO4:7 Ca2SiO4 sample was very hard and did not disintegrate until bombarded by X rays. The 1 Mg2SiO4:7 Ca2SiO4 mixture produced a body that dusted on cooling and gave definite X-ray evidence that merwinite (Ca3MgSi2O8) formed. Experiments were made to determine the suitability of AlPO4 as a major phase in a ceramic body. (Author)

Descriptors :   *CERAMIC MATERIALS, *ELECTRON TUBES, ALKALINE EARTH COMPOUNDS, ALUMINUM COMPOUNDS, BARIUM COMPOUNDS, BORON COMPOUNDS, CALCIUM COMPOUNDS, IMPURITIES, MAGNESIUM COMPOUNDS, OXIDES, PHASE STUDIES, PHOSPHATES, QUARTZ, SILICATES, SILICON COMPOUNDS, STABILIZATION, SYNTHESIS, TETROXIDES, THERMAL EXPANSION

Distribution Statement : APPROVED FOR PUBLIC RELEASE