Combustion synthesis of transition-metal nitrides
A new process, using sodium azide (NaN/sub 3/) as a solid source of nitrogen, for the production of transition-metal nitride materials is presented. For example, a -325 mesh Ti powder with average particle size of 22..mu.. was mixed with NaN/sub 3/ powder in a glass jar on a vibratory mill for 5 minutes. The powder was cold-pressed into cylinders or poured into quartz crucibles. The quartz crucible containing the powder was placed in a glove box which was pumped down to approx. 200 ..mu... After back-filling with nitrogen to one atmosphere the powder was ignited by a tungsten coil which was in contact with the surface of the powder. The combustion temperature was estimated to be at least 2200/sup 0/C at the maximum point. A thick cloud of smoke, consisting of Na vapor and other volatile gases from the initial powders, evolved during reaction. The reaction product is a loose, friable powder that is easily removed from the quartz crucible. The average grain size of the TiN powder is 10..mu.. as shown in a SEM micrograph. X-ray-diffraction analysis verified the powder to be TiN with no trace of Ti metal. The advantages of this process are high-purity products, high rates of synthesis, and energy efficient since no furnaces are required.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6452437
- Report Number(s):
- UCRL-87794; CONF-821133-4; ON: DE83009120
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
CHEMICAL REACTIONS
COHERENT SCATTERING
COMBUSTION
DATA
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
METALS
MICROSCOPY
NITRIDES
NITROGEN COMPOUNDS
NUMERICAL DATA
OXIDATION
PNICTIDES
REFRACTORIES
SCANNING ELECTRON MICROSCOPY
SCATTERING
SODIUM COMPOUNDS
SODIUM NITRIDES
SYNTHESIS
THERMOCHEMICAL PROCESSES
TITANIUM
TITANIUM COMPOUNDS
TITANIUM NITRIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE
X-RAY DIFFRACTION