SOME PROPERTIES OF BERYLLIUM OXIDE AND – COLUMBIUM CERAMALS

摘要

Because of the potentially excellent refractory properties of beryllium oxide, a brief investigation was made of its short-time tensile strength at a temperature of 1800° F and relative thermal-shock resistance from temperatures of 1600° and 2000° F to room temperature. The effect of additions of 2, 5, 8, 10, 12, and 15 percent by weight of columbium metal on the thermal-shock resistance of beryllium oxide was studied.nMetallographic examination indicated that the metallic phase coalesced into pockets. Beryllium oxide had a tensile strength as high as 6160 pounds per square inch at 1800° F. The original columbium underwent a phase change, as indicated by X-ray analysis of the ceramals. The addition of columbium up to 15 percent by weight failed to improve the resistance to thermal shock. The phase change and the failure of the columbium to wet the beryllium oxide may explain the poor thermal-shock resistance of these ceramals.