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Properties of Manganese-copper Alloys Prepared from Metal Powders.
Holamn-JL; Crosby-RL; Neumeier-LA
NTIS: PB 80-125867 :32 pages
The Bureau of Mines has extended its previous development of cast mn- cu damping alloys to powder metallurgy (p/m) consolidation of alloys containing 55 to 75 wt-pct mn. Blends of minus 200-mesh elemental powders were compacted cold in directional and isostatic presses. With 1 pct binder, typical green densities ranged between 76 and 80 pct of theoretical when pressing at 30 or 48 tsi. Green strength increased with compacting pressure and copper content. As-sintered tensile strengths ranged to 60,000 psi for hydrogen-sintered 60mn- 40cu alloy, along with 5-pct elongation. Sintering was effective when holding for 1 hr at maximum temperatures of 900 deg to 1,040 deg c, dependent on composition. Strength and ductility were considerably lower than for equivalent cast alloys. When aged to the damping conditions, alloys containing 60 to 70 pct mn exhibited >40 pct specific damping capacity (sdc) at 5,000-psi stress, considerably higher than values reported for equivalent cast material. Effects of 1 or 3 pct sn or zn additions on sdc and other properties were assessed. Trials were conducted on consolidating rings and gears of the 65mn-35cu alloy on industrial-type p/m equipment.
IH; Report of Investigation;
NTIS Accession No.
NTIS: PB 80-125867
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division