Dynamic consolidation of cubic boron nitride and its admixtures

Journal Article · Thu Sep 01 00:00:00 EDT 1988 · J. Mat. Res.; (United States)

DOI:https://doi.org/10.1557/JMR.1988.1010· OSTI ID:6910892

Tan, H; Ahrens, T J

Cubic boron nitride (C-BN) powders admixed with graphite-structured boron nitride powder (g-BN), silicon carbide whisker (SCW), or silicon nitride whisker (SNW) were shock compacted to pressures up to 22 GPa. Unlike previous work with diamond and graphite (D. K. Potter and T. J. Ahrens, J. Appl. Phys. 63, 910 (1987)) it was found that the addition of g-BN inhibited dynamic consolidation. Good consolidation was achieved with a 4--8 ..mu..m particle size C-BN powder admixed with 15 wt.% SNW or 20 wt.% SCW. Whereas a 37--44 ..mu..m particle size C-BN mixture was only poorly consolidated. Scanning electron microscopy (SEM) analysis demonstrate that SCW and SNW in the mixtures were highly deformed and indicated melt textures. A skin heating model was used to describe the physics of consolidation. Model calculations are consistent with SEM analysis images that indicate plastic deformation of SCW and SNW. Micro-Vickers hardness values as high as 50 GPa were obtained for consolidated C-BN and SNW mixtures. This compares to 21 GPa for single-crystal Al/sub 2/O/sub 3/ and 120 GPa for diamond.

• Research Organization: Seismological Laboratory, California Institute of Technology, Pasadena, California 91125
• OSTI ID: 6910892
• Journal Information: J. Mat. Res.; (United States), Vol. 3:5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON NITRIDES
COMPACTING
ADDITIVES
GRAPHITE
POWDERS
SCANNING ELECTRON MICROSCOPY
SHOCK WAVES
VERY HIGH PRESSURE
BORON COMPOUNDS
CARBON
ELECTRON MICROSCOPY
ELEMENTAL MINERALS
ELEMENTS
MICROSCOPY
MINERALS
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
PNICTIDES
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication