Titanium-boron mixtures as variable heat sources

Conference · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6912971

Begeal, D R ^[1]; Munger, A C ^[2]

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1. Sandia National Labs., Albuquerque, NM (USA)
2. EG and G Mound Applied Technologies, Miamisburg, OH (USA)

The reaction between titanium and boron to form titanium diboride is one of the hottest pyrotechnic reactions in common usage and offers the advantage of being a solid state gasless reaction. Based on the work of Hart, a heat source with a variable output has been developed that utilizes this pyrotechnic. The device was designed to deliver the heat across a 0.26 inch inner diameter hemispherical bulkhead of a material and thickness that can be specified by the user. For evaluation purposes, the bulkhead was 0.036 inches thick stainless steel. The maximum temperature on the tip of the bulkhead was 950{degree}C for the pure reactants and 680{degree}C for blends diluted with 30 weight percent of alumina. Further, the temperature was uniform within {plus minus}20{degree}C across a 2 millimeter diameter on the tip of the bulkhead, and the temperature rise characteristics were repeatable. Ignition of the titanium/boron heat powder was accomplished by first igniting an adjacent charge of titanium subhydride/potassium perchlorate with a one ohm bridge wire. The header was constructed of inconel, a glass ceramic insulator, and hastelloy pins. The ignition and subsequent burn of the titanium/boron was nearly instantaneous, thus the thermal output was dependent only on the heat transfer properties of the materials and geometry involved. Therefore, the user can tailor the blend dilution and the bulkhead characteristics to provide a large range of precise heat outputs. Typical uses of this heat source include timely ignition of other materials, or heating confined gas to perform useful mechanical work. Achievement of the precise heat output required special attention to the purity of the titanium and boron and to the blending process. These aspects, as well as those described above will be described. 6 refs., 9 figs., 3 tabs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6912971
• Report Number(s): SAND-90-0005C; CONF-900792--2; ON: DE90009729
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250800* -- Energy Storage-- Chemical
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BORIDES
BORON
BORON COMPOUNDS
CHALCOGENIDES
DISPERSIONS
ELEMENTS
HEAT SOURCES
IGNITION
METALS
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
POWDERS
PYROTECHNIC DEVICES
SEMIMETALS
TITANIUM
TITANIUM BORIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS