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U.S. Department of Energy
Office of Scientific and Technical Information

COLUMBIUM POWDER METALLURGY PROJECT QUARTERLY PROGRESS REPORT NO. 2, PERIOD COVERED AUGUST 1 TO OCTOBER 31, 1960

Technical Report ·
OSTI ID:4837199

Significant advances were made in the consolidation of F-48 by vacuum hot pressing and by cold pressing and sintering. The arc plasma deposition method has proven unenticing and will be dropped because of difficulties in maintaining purity and production levels. Workability of samples made from hot pressed or cold pressed parts is significantly better than arc cast material. One tensile specimen was made from hot pressed and rolled prealloyed powder. The strength and ductility compared favorably at 2200 deg F with values for sheet made from an arc cast ingot. Evaluation of hot pressed compacts of prealloyed powders show: particle size has a small but consistent effect on the density of a compact, finer Particles yield denser billets; the denser billets are somewhat harder at room temperature and much more difficult tc roll; and the conditions for consolidation for optimum rollability are close to the middle of the experimental design. Hot pressing conditions are 1.25 hr at 3400 deg F and 3500 psi. Cold pressing and sintering has not evolved any superiority of prealloyed powders over elemental powders in homogeneity, density, or forgeability. Particle size has no influence in this phase. Present procedure calls for isostatic pressing at 37000 psi and vacuum sintering in two steps to 4172 deg F. Pretreating powders by ball-milling and vacuum degassing at 3092 deg F have enhanced compactibility and handling of the green billets. (N.W.R.)

Research Organization:
General Electric Co. Flight Propulsion Lab. Dept., Cincinnati
NSA Number:
NSA-15-029664
OSTI ID:
4837199
Report Number(s):
NP-10661
Country of Publication:
United States
Language:
English