Graphite whisker

R. Bacon, Growth, structure, and properties of graphite whiskers, J. Appl. Phys. 31, 283—290 (1960). 

The theoretical mechanical strength of perfect carbon fibers is between 14 and 20 X 10 psi, while the Young s modulus for graphite whiskers was calculated as 145 X 10 . Diamond (the most dense crystalline C modification at 3.5 g/cc, compared with graphite at 2 to 2.22 g/cc) has a Young s... 

Sodium nitrate Strontium nitrate Graphite Whisker Fiber... 

Figure IS. Size and distortion separation. Integral breadth iss against l2 for the 001 reflections of carbon fiber and graphite whisker. Electron diffraction traces with 001 reflections resolved from hkO reflections.

PPN was converted to a graphite whisker with one-dimensional graphite chains oriented normal to the axis. 

The microstructure of the initial titanium-graphite mixture is shown in Figure 62a. When the temperature in the combustion wave reaches 1660°C, titanium melts. It was determined from quenching results that a thin film ( 0.1 / m) of the Ti melt spreads over the solid carbon surface with simultaneous formation of titanium carbide grains (Fig. 62b). Small rounded TiC particles were observed to appear within the liquid rather than in the form of a continuous product layer (Rogachev et al, 1987). To illustrate this fact further, the typical microstructure formed during combustion reaction of titanium melts with graphite whiskers (10 /.im in diameter) is shown in Fig. 62c. 

Fig. 62. Characteristic microstructures during synthesis of Ti-C system (a) initial reactant mixture, Ti-I-graphite (b) initial product formation (c) formation of TiC grains in Ti melt around graphite whiskers.

The pyrolysis reactions take place at temperatures between 800 and 3000°C, both in the gas phase and on the substrate surface. Their property mix can be varied within wide limits by appropriate choice of process parameters. The production of an isotropic structure is just as possible as the obtaining of spiral, columnar or extremely anisotropic laminar structures. Graphite whiskers can also be produced. 

A battery of complementary techniques is often necessary (and always desirable) to provide reliable, applications-oriented characterization of the bulk properties of (catalytic) carbon materials. Arguably the most useful ones are transmission electron microscopy (TEM), thermoelectric power (TEP) measurements, electron spin resonance (ESR) spectroscopy coupled with a superconducting quantum interference device (SQUID), and Raman spectroscopy. For example, among the recently reported virtues of Raman spectroscopy is the identification of graphite whiskers [152,153] in three carbonaceous chondrite meteorites (M. Fries and A. Steele, Science Online, Feb. 28, 2008), which contain some of the oldest matter in the solar system and has thus generated tremendous interest among astrophysicists. 

Thermoset plastic, Thermoplastic Glass, aramid, carbon, graphite, whisker, metal, etc. Mechanical strength, wear resistance, elevated temperature resistance, energy absorption, thermal stability... 

Aluminum alloy Titanium alloy High tensile steel Special glass fiber Epoxy fiberglass Silica Fiber Epoxy carbon fiber Boron fiber Carbon fiber Iron whisker SIC whisker Graphite whisker... 

K. Zaghib, K. Tatsumi, H. Abe, T. Ohsaki, Y. Sawada, S. Higuchi, J. Power Sources 1995, 54, 435-439. Electrochemical behavior of an advanced graphite whisker anodic electrode for lithium-ion rechargeable batteries. 

Ion bombardment processes Short carbon/graphite whiskers 2.2 [7]... 

Silicon carbide whiskers can also be synthesized by carbothermal reduction of silicon nitride [10]. Silicon nitride decomposes >1300°C, silicon melts at 1410°C, and reacts with graphite. Whisker formation in this process is initiated >1400°C and can be completed between 1550... 

M. Hatano, T. Ohsaki and K. Arakawa, Graphite whiskers by new process and their composites, SAMPE Symposium Series, 30,1467-1476 (1985). 

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