High energy rate densification and forming of metal powders. Final report, 1 June 1963-1 June 1966

Technical Report · Mon Aug 01 04:00:00 EDT 1966

OSTI ID:5527025

Hay, W S

The object of the original program (Part I) was to (1) develop a production method for slip casting thin-walled shapes from tungsten powder and (2) improve the properties of powder forms by high-energy-rate (HER) densification (pneumatic-mechanical and chemical explosive) processes. A slip casting method for tungsten was developed, but attempts to HER densify powder forms were unsuccessful. The program was then revised (Part II) to develop a manufacturing method for forming parts from powdered metals or alloys directly by using HER techniques. The basic HER method developed involves (1) RT compaction of the powder to form a briquette and (2) extruding or forging this briquette after preheating to the final shape desired. Optimized techniques were developed for briquetting, free extruding, and closed-cavity extruding 4600 steel-graphite, 18-9 steel, and nickel-thoria powder. Photomicrographic analysis and tensile-test data were obtained on all specimens. Data indicates that 4600 steel-0.20% graphite HER extrusions or closed-cavity specimens had ultimate tensile strengths 15% greater than commercial 4620 steel. Nickel-thoria HER powder specimens had room-temperature strengths much higher than comparable commercial material--38% higher for extrusions and 17% for closed-cavity tensile specimens. HER formed nickel-thoria specimens had much lower hot strength (1600 - 1900 F) than the commercial product which is cold drawn. Two production-type parts were made using 4600 steel-graphite and nickel-thoria powder--one by extrusion and one by forging techniques. Although the parts as made had minor flaws, the feasibility of making small production parts by the HER technique was demonstrated.

• Research Organization: General Dynamics Corp., Fort Worth, TX (USA)
• OSTI ID: 5527025
• Report Number(s): AD-803172/6/XAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
360301 -- Composite Materials-- Preparation & Fabrication-- (-1987)
ACTINIDE COMPOUNDS
ALLOYS
ANNEALING
ATMOSPHERES
BINDERS
CARBON
CARBON ADDITIONS
CASTING
CHALCOGENIDES
COLD WORKING
COMPOSITE MATERIALS
CONTROLLED ATMOSPHERES
DIES
ELEMENTAL MINERALS
ELEMENTS
EXTRUSION
FABRICATION
FEASIBILITY STUDIES
FORGING
FURNACES
GRAPHITE
HEAT TREATMENTS
HOT WORKING
IRON ALLOYS
IRON BASE ALLOYS
MARAGING STEELS
MARTENSITE
MATERIALS
MATERIALS WORKING
MECHANICAL PROPERTIES
METALLURGY
METALS
MINERALS
NICKEL ALLOYS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHOTOGRAPHY
PHOTOMICROGRAPHY
POWDER METALLURGY
SLIP CASTING
STEELS
TENSILE PROPERTIES
THORIUM COMPOUNDS
THORIUM OXIDES
TRANSITION ELEMENTS
TUNGSTEN