High performance heavy alloys by alloying and process control. Final report, 15 August 1991-14 May 1993
The kinetics and processing conditions of liquid phase sintering (LPS) have been addressed in the development of a novel heavy alloy, W-Ni-Mn. Solubility criteria were considered in the selection of manganese as an alloying element to the W-Ni system. The addition of manganese resulted in a depressed melting point of the matrix and consequently sintering in this system was achieved at temperatures 300 deg C lower than in the conventional heavy alloys. Concurrent with solubility criteria, the rearrangement stage in liquid phase sintering was treated. When capillary and viscous drag forces are accounted for, the time scales in rearrangement were found to be in the microseconds range for metal systems. On the other hand, heat transfer was found to be the rearrangement time limiting factor for metallic specimens with time scales in the range of seconds. Further, depending on the green density and the system under consideration, there exists specific specimen dimensions where a transition from heat transfer to capillary control over the rearrangement time. These dimensions are, however, in the micrometer range. Tungsten heavy alloys, Grain growth, Alloying, Mechanical properties, Microprobe analysis.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States). Davey Lab.
- OSTI ID:
- 5730930
- Report Number(s):
- AD-A-271129/9/XAB; CNN: DAAL03-91-G-0309
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MANGANESE
METALLURGICAL EFFECTS
SINTERING
PROCESS CONTROL
REACTION KINETICS
TUNGSTEN BASE ALLOYS
GRAIN GROWTH
HEAT TRANSFER
MANGANESE ADDITIONS
MECHANICAL PROPERTIES
MELTING POINTS
NICKEL ALLOYS
SOLUBILITY
ALLOYS
CONTROL
ELEMENTS
ENERGY TRANSFER
FABRICATION
KINETICS
MANGANESE ALLOYS
METALS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRANSITION TEMPERATURE
TUNGSTEN ALLOYS
360101* - Metals & Alloys- Preparation & Fabrication