INVESTIGATION OF SINTERABLE POWDERS AND BERYLLIUM OXIDE PROPERTIES. Quarterly Report No. 1 for February 15, 1959 through April 30, 1959

Technical Report · Fri May 15 04:00:00 EDT 1959

OSTI ID:4246155

Smalley, A K; Quirk, J F; Duckworth, W H

Emphasis during the first quarter was on exploratory experiments with MgO and BeO and on planning a laboratory program. A tentative research program for the 12-month period was developed. Briefly, the program consists of a laboratory study of the effects ot processing variables and the character of the starting oxide powder on internal body structures, and correlation of these body- structure characteristics with strength and other properties of the ceramics. Initially, fabrication experiments were made on MgO ceramics, pending receipt of a supply of high-purity BeO powder. The effects of forming pressure and sintering temperature on densifications strength, and crystal size of ceramics made from a selected MgO powder are discussed. Bulk density, room-temperature modulus of rupture, and crystal size of sintered Mg0 bars varied little between compacting pressures of 50,000 and 100,000 psi. Crystal size increased with sintering temperature in specimens sintered at 2800, 2950, and 3100 F. Roomtemperature modulus of ruptiire appeared to be only slightly affected by changes in sintering temperature. This small variation in moduli-of-rupture values showed the expected inverse relationship with crystal size. A sample of UOX-grade BeO contained less than 450 ppm of cation impurities. Sintering trials indicated that speeimens having bulk densities up to 98.5% of theoretical could be prepared by suitable physical processing of the powder with subsequent sintering for 4 hrs at 3000 F in hydrogen. (auth)

• Research Organization: Battelle Memorial Inst., Columbus, Ohio
• NSA Number: NSA-13-014521
• OSTI ID: 4246155
• Report Number(s): NP-7528
• Country of Publication: United States
• Language: English

Related Subjects

BERYLLIUM OXIDES
CERAMICS
DENSITY
GRAIN SIZE
HEAT TREATMENTS
HYDROGEN
IMPURITIES
MAGNESIUM OXIDES
METALLOGRAPHY
METALLURGY AND CERAMICS
PRESSURE
SINTERING
TEMPERATURE
TENSILE PROPERTIES