Chemical vapor infiltration of TiB[sub 2] composites

Technical Report · Fri Jan 01 00:00:00 EST 1993

DOI:https://doi.org/10.2172/6773268· OSTI ID:6773268

Besmann, T M; Miller, J H; Cooley, K C; Lowden, R A ^[1]; Starr, T L ^[2]

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1. Oak Ridge National Lab., TN (United States)
2. Georgia Tech Research Inst., Atlanta, GA (United States)

Efficiency of the Hall-Heroult electrolytic reduction of aluminum can be substantially improved by the use of a TiB[sub 2] cathode surface. The use of TiB[sub 2], however, has been hampered by the brittle nature of the material and the grain-boundary attack of sintering-aid phases by molten aluminum. In the current work, TiB[sub 2] is toughened through the use of reinforcing fibers, with chemical vapor infiltration (CVI) used to produce pure TiB[sub 2]. It has been observed, however, that the formation of TiB[sub 2] from chloride precursors at fabrication temperatures below 900 to 1000[degrees]C alloys the retention of destructive levels of chlorine in the material. At higher fabrication temperatures and under appropriate infiltration conditions, as determined from the use of a process model, a TIB[sub 2]THORNEL P-25 fiber composite, 45 mm in diam and 6 mm thick, has been fabricated in 20 h. The material has been demonstrated to be stable in molten aluminum in short-duration tests.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6773268
• Report Number(s): ORNL/TM-12214; ON: DE93006941
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
SMELTING
TITANIUM BORIDES
REINFORCED MATERIALS
CATHODES
COMPOSITE MATERIALS
FIBERS
BORIDES
BORON COMPOUNDS
ELECTRODES
ELEMENTS
MATERIALS
METALS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360203* - Ceramics
Cermets
& Refractories- Mechanical Properties
360101 - Metals & Alloys- Preparation & Fabrication