Matrix composition effects on the tensile properties of tungsten-molybdenum heavy alloys
- Southwest Research Inst., San Antonio, TX (US)
- Rensselaer Polytechnic Inst., Troy, NY (US)
Tungsten-base heavy alloys are liquid-phase sintered from mixed tungsten, nickel, and iron powders. The sintered product is a composite consisting of interlaced tungsten and solidified matrix (W-Ni-Fe) phases. These alloys are most useful in applications requiring high density, strength, and toughness. The design of improved tungsten heavy alloys has been the subject of several research investigations. Much success has taken place through improved processing, but parallel compositional studies have resulted in new microstructure-property combinations. As part of these investigations, the Ni/Fe ratio has been varied, with the general conclusion that optimal strength and ductility occur with a ratio between 2 and 4. Brittle intermetallic phases can form outside of this composition range. Historically, a 7/3 Ni/Fe ratio has been selected for processing studies. Recently, others reported higher ductilities and impact energies for 90 and 93 pct W heavy alloys with the 8/2 Ni/Fe ratio. Alternatively, these alloys can be strengthened by both solid solution and grain size refinement through incorporation of molybdenum, tantalum, or rhenium. These additions are soluble in both the tungsten and matrix phases and retard solution-reprecipitation during liquid phase sintering. In this study, the alloy composition was varied in the nickel/iron ratio and molybdenum was partially substituted for tungsten. The sintered tensile properties are assessed vs these compositional variations.
- OSTI ID:
- 6022811
- Journal Information:
- Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (USA), Vol. 21:5; ISSN 0360-2133
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MATRIX MATERIALS
CHEMICAL COMPOSITION
MOLYBDENUM ALLOYS
TENSILE PROPERTIES
TUNGSTEN ALLOYS
DENSITY
DUCTILITY
HYDROGEN
IMPACT STRENGTH
IRON
LIQUID PHASE EPITAXY
MICROSTRUCTURE
NICKEL
POWDERS
SINTERING
ALLOYS
CRYSTAL STRUCTURE
ELEMENTS
EPITAXY
FABRICATION
MATERIALS
MECHANICAL PROPERTIES
METALS
NONMETALS
PHYSICAL PROPERTIES
TRANSITION ELEMENTS
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies
360104 - Metals & Alloys- Physical Properties