INVESTIGATION OF THE EFFECTS OF PROCESSING VARIABLES AND FABRICATION TECHNIQUES UPON THE PROPERTIES OF INTERMETALLIC COMPOUNDS. Progress Report No. 4, January 1, 1961-March 31, 1961. Technical Report No. 210-229

Technical Report · Sat Apr 15 04:00:00 EST 1961

OSTI ID:4080012

Truesdale, R S; Lympany, B B; Grala, E M; Bielawski, C A; Paine, R M; Beaver, W W

Sinterability studies were conducted on Nb/sub 2/Be/sub 1//sub 7/ coldpressed compacts. The variables studied were particle size, iron content, and sintering time and temperature in relation to density, grain size, and strength. High modulusof-rupture strengths (56,700 to 65,000 psi) were obtained for fine-grained (21-micron) materials of greater than 95% of theoretical density tested at 2300 to 2500 deg F. Fine grain size resulted from sintering fine powders (7.8 micron) at 3020 deg F for two hours. Small particle size powders provided lower sintering temperatures and broader sintering ranges which resulted in high density and fine grain size. The feasibility of fabricating intermetallic shapes by isostatic pressing, extrusion, investment casting, and flame spraying was also demonstrated. Large shapes were fabricated by cold pressing and sintering and by hot pressing. Upsetting studies conducted on NbBe/ sub 1//sub 2/, Nb/sub 2/Be/sub 1//sub 7/, and Nb/sub 2/Be i/sub 9/ revealed that Nb/sub 2/Be/sub 1//sub 9/ had the highest rate of reduction, which was approximately 42% per minute at 3000 deg F. Nb/sub 2/Be/sub 1//sub 7/ had a lower rate of reduction but provided much higher resistance to cracking. Changes observed in the microstructure of these materials upset at elevated temperatures included some grain growth and a slight amount of preferred orientation. Nb/sub 2/Be/sub 1//sub 7/ was the most stable compound at 3000 deg F. (auth)

• Research Organization: Brush Beryllium Co., Cleveland
• NSA Number: NSA-15-021114
• OSTI ID: 4080012
• Report Number(s): NP-10303
• Country of Publication: United States
• Language: English

Related Subjects

BERYLLIUM
CASTING
COMBUSTION
COMPACTING
CRACKS
CRYSTALS
DENSITY
EFFICIENCY
EXTRUSION
FABRICATION
GRAIN SIZE
HIGH TEMPERATURE
INTERMETALLIC COMPOUNDS
IRON
LATTICES
METALLOGRAPHY
METALS, CERAMICS, AND OTHER MATERIALS
NIOBIUM
POWDERS
PRESSURE
QUANTITY RATIO
REDUCTION
SINTERING
SPUTTERING
STABILITY
TEMPERATURE
TENSILE PROPERTIES
TESTING
VOLUME