Structural evolution in niobium beryllides during mechanical alloying
- Lockheed Missiles and Space Co., Inc., Palo Alto, CA (United States). Research and Development Div.
This paper reports that the mechanical alloying (MA) technique has been realized as a method for producing amorphous alloy powders since the first inception. In principle, MA involves solid-state, crystalline, elemental (or compound) powders as starting materials, which are mechanically energized by a variety of milling processes (e.g., Spex milling and vibratory milling), under various environments, for different times. Since its advent, MA has served as a powerful tool for the investigation of amorphization/crystallization of a large number of alloy systems, for example Ni-Nb, Au-La, Ni-Ti, Ti-Si, Ni-Zr, and several transition metal-Zr alloys. As a result, new phases, both crystalline and amorphous, have been discovered, and previously known alloys have been produced in a simpler way by MA. One of the major advantages of MA is the ease of preparing amorphous alloys containing both high and low melting point constituents, for example Al-Ta and Al-Nb quenching methods. Moreover, the MA technique, combined with a crystallization process by annealing at elevated temperatures, is also perceived as a practical way of preparing intermetallic compounds with little (or no) tolerance for compositional variation. In contrast, conventional casting and hot-pressing techniques normally produce intermetallics consisting of two-phase mixtures, which are a result of constitutional supercooling and sluggish solid-state reactions.
- OSTI ID:
- 7019451
- Journal Information:
- Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 27:7; ISSN SCRMEX
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
AEROSPACE INDUSTRY
ALLOYS
AMORPHOUS STATE
ANNEALING
BERYLLIUM ALLOYS
CHEMICAL COMPOSITION
CORROSION RESISTANCE
CRYSTAL STRUCTURE
CRYSTALLIZATION
DISPERSIONS
ELEMENTS
FABRICATION
FLUID FLOW
HEAT RESISTANT MATERIALS
HEAT TREATMENTS
HOT PRESSING
INDUSTRY
INTERMETALLIC COMPOUNDS
MATERIALS
MATERIALS TESTING
MATERIALS WORKING
METALS
MICROSTRUCTURE
MIXTURES
NIOBIUM ALLOYS
PHASE TRANSFORMATIONS
POWDERS
PRESSING
REFRACTORY METALS
TESTING
THERMOMECHANICAL TREATMENTS
TWO-PHASE FLOW