Accession Number : AD0612775

Title :   PRODUCTION ENGINEERING MEASURE FOR BERYLLIUM OXIDE AND PARTS PRODUCED FROM IMPORTED ORES.

Descriptive Note : Quarterly progress rept. no. 5, 1 Jul-30 Sep 64,

Corporate Author : BERYLLIUM CORP READING PA

Personal Author(s) : Blum,J. F.

Report Date : 30 SEP 1964

Pagination or Media Count : 25

Abstract : Dielectric properties were evaluated on specimens produced by various fabrication techniques. The average dielectric strength values for samples fired at 1560C were about 250 volts/mil. Gross differences were not noted as a function of fabrication technique. Dielectric constant and loss factor values were about 6.4 and 0.0007 respectively for as-sintered specimens. Machined samples showed an increased dielectric loss over the assintered specimens when measured following a water pretreatment as specified by MIL-I-10A. Firing temperature versus grain size studies on 99 per cent BeO compacts showed that average grain size ranged from about 13 microns at 1460C to 33 microns at 1560C. Average grain sizes were fairly constant in the firing temperature range 1510 - 1560C, but a significant change was noted at 1490C. Fired densities were about 97 per cent of theoretical from 1490 - 1560C. The fired density at 1460C was 96 per cent of theoretical. Flexural strength results showed a slight difference between test specimens prepared from fine and coarse grained samples with an average value of 26,900 psi for 13 micron material and 24,200 for 33 micron test specimens. However, the difference was not as large as anticipated and the results may be influenced more strongly by specimen preparation than by actual material differences. (Author)

Descriptors :   (*CERAMIC MATERIALS, ELECTRONIC EQUIPMENT), (*BERYLLIUM COMPOUNDS, OXIDES), (*ELECTRONIC EQUIPMENT, CERAMIC MATERIALS), (*POWDER METALLURGY, MECHANICAL WORKING), POWDERS, SINTERING, BINDERS, MIXTURES, DIELECTRIC PROPERTIES, HEAT TREATMENT, DENSITY, PARTICLE SIZE, MICROSTRUCTURE, TENSILE PROPERTIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE