HOT-PRESSING OF PURE OXIDE CERAMICS

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Zh. Vses. Khim. Obshchestva im. D.I. Mendeleeva

OSTI ID:4118964

Poluboyarinov, D N; Shal'nov, E I

Two types of apparatuses for hot pressing ceramic materials, with detailed diagrams of each, are described. The first consists of a high-frequency generator, hydraulic press, graphite press mold, and system for delivering energy to a graphite receiver. Combined heating by the thermal radiation of the receiver and press mold itself, heated by induction current, permits a more rapid increase in the temperature of the press mold, more unifoim heating over the cross section, and accurate control of the composition of the medium. The second setup consists of a tubular graphite resistance furnace, placed between the two plates of a hydraulic press, which serve as electrical contacts. The press mold is either a replaceable graphite heater of a tubular furnace or a press mold inserted into the space of the tubular furnace, being indirectly heated there. In this case more powerful equipment is required, but greater safety during operation is provided. The preparation of dense ceramics by hot-pressing from beryllium oxide, magnesium oxide, calcium oxide, and aluminum oxide is discussed, and data are given on: shrinkage during sintering and hot-pressing, variation of the density during hot-pressing, dependence of the volume weight on the crystal dimensions, crystal dinmensions as a function of the temperature during hot- pressing and purity of the initial material, and thermal shockresistance (BeO); thickening during hot-pressing, specific surface, equivalent spherical diameter, pressure needed to produce a set density (MgO); variation of the density under various systems of treatment (CaO). Data and empirical equations are given for the density variation of seven different types of alumina and analogous comparison compounds under various annealing systems and photomicrographs of the microstructure of hot-pressed Al/sub 2/O/sub 3/ after treatment at three different temperatures. (TCO)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-007175
• OSTI ID: 4118964
• Journal Information: Zh. Vses. Khim. Obshchestva im. D.I. Mendeleeva, Journal Name: Zh. Vses. Khim. Obshchestva im. D.I. Mendeleeva Vol. Vol: 8
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALUMINUM OXIDES
ANNEALING
BERYLLIUM OXIDES
CALCIUM OXIDES
CASTING
CERAMICS
COMPACTING
CONTROL
CRYSTALS
DEFORMATION
DENSITY
DISTRIBUTION
ELECTRIC CONDUCTIVITY
EQUATIONS
FURNACES
GRAPHITE
HEAT TREATMENTS
HEATING
HOT WORKING
IMPURITIES
INDUCTION
MACHINE PARTS
MAGNESIUM OXIDES
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
OXIDES
PLANNING
PRESSURE
SINTERING
TEMPERATURE
THERMAL STRESSES
TUBES
VOLUME