APPLICATIONS OF ULTRASONIC ENERGY. TASK 2. ULTRASONIC METAL AND CERAMIC POWDER PROCESSING. TASK 3. ULTRASONIC INSTRUMENTATION. Progress Report No. 28, June 1, 1961 to July 31, 1961

Technical Report · Fri Aug 18 04:00:00 EDT 1961

OSTI ID:4804969

Continued application of ultrasonic activation to slip casting molds after the mold was filled resulted in removal of significant quantities of water from the slip. In the preparation of cylindrical slip-cast cermet bars, activation for 5 min after filling resulted in green specimens with 54% less water than nonactivated control specimens of the same composition. Cylindrical ceramic specimens are being prepared under controlled conditions to study the effects of ultrasonic power and activation time on properties. One group of specimens showed improvement of green density with ultrasonic activation and further improvement resulting from continued ultrasonic activation after the mold was completely filled. Stainless steel-clad tubes filled with arc-fused, ground, and sized ThO/sub 2/ -UO/sub 2/, ultrasonically compacted to 91.8% of theoretical density, were examined by x rays and found to be free of voids and gross density variations. By measurement of the outside diameters of the tubes, they were found to be also free of distortion. Standard pelleting techniques and the use of an ultrasonically activated punch eliminated problems of capping and cracking of pellets indicative of relative freedom from residual stresses. Without ultrasonic activation of the punch no usable pellets were obtained. It was shown that calcium fluoride cylinders can be produced at temperatures well below the normal hot pressing temperature through the use of an ultrasonically activated punch. Ultrasonic instrumentation is under investigation for specialized use in nuclear reactor operation. Advances in the techniques for the detection and measurement of incipient boiling, foam-level, and changes in gas or liquid suspension properties are reported. Earlier indications that localized incipient boiling in critical areas of water-cooled reactors could be detected by the use of ultrasonic sensing elements of modest face diameter were substantiated by results obtained using a 1/16-in.-diameter probe. Ultrasonic standing-wave-ratio measurement was shown to have sufficient sensitivity to detect and to measure changes in the water-content of simulant foams. This was validated by tests on actual foam generated from steam and water such as would be encountered in reactors of the EBWR type. A simple bench test of a resonant column for gas- dispersed-particle measurement in fluidized bed reactors indicated the expected reduction in amplitude. The ultrasonic impedance ratio as measured by a sensing element in a liquid suspension (simulating the thoria blanket in an aqueous homogeneous reactor) was shown to vary with the concentration of the liquid- dispersed particles. Indication of particle-size dependency was confirmed. (auth)

• Research Organization: Aeroprojects, Inc., West Chester, Penna.
• NSA Number: NSA-16-005687
• OSTI ID: 4804969
• Report Number(s): NYO-9584
• Country of Publication: United States
• Language: English

Related Subjects

ACTIVATION
BOILING
CALCIUM FLUORIDES
CASTING
CERAMICS
CERMETS
CRACKS
DENSITY
ELECTRIC ARCS
ENERGY
ENRICHMENT
GASES
GRAIN SIZE
LIQUIDS
MELTING
METALS
METALS, CERAMICS, AND OTHER MATERIALS
PELLETS
POWDERS
POWER
PREPARATION
REACTORS
STAINLESS STEELS
STRESSES
SUSPENSIONS
TEMPERATURE
TESTING
THORIUM OXIDES
TUBES
ULTRASONICS
URANIUM DIOXIDE
WATER
WATER COOLANT
X RADIATION