Graphitization


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graphitization

[‚graf·əd·ə′zā·shən]
(organic chemistry)
The formation of graphitelike material from organic compounds.

Graphitization

 

the formation (deposition) of graphite in iron, nickel, cobalt, and other metal alloys in which carbon is contained in the form of unstable chemical compounds, carbides. At high temperatures the carbide is completely replaced by graphite. The rate of graphitization increases upon a rise in temperature, as well as upon preliminary hardening, deformation, and irradiation.

Graphitization of steel usually adversely affects the mechanical properties of steel (it reduces the strength and plasticity). At the same time the graphite, which has lubricating properties, increases the durability of the articles. The graphitization of iron alloys is used in producing articles from cast iron and graphitic bearing and die steel. Silicon, or less frequently aluminum, is introduced into steel or iron to accelerate graphitization. The graphitization of a number of alloys (tool-cutting, spring, boiler, and other steels) reduces their operating quality and is undesirable. Graphitization can be arrested by introducing additives (chromium or manganese), which increase the stability of the carbides. The term “graphitization” is sometimes used to designate the formation of graphite in iron-carbon alloys that do not contain carbides. Graphite is separated from alloys that are supersaturated with carbon upon their solidification and subsequent cooling.

REFERENCES

Grafitizatsiia stali. Kiev, 1961.
Girshovich, N. G. Kristallizatsiia i svoislva chuguna ν otlivkakh. Moscow-Leningrad, 1966.
Krishtal, M. A., and E. G. Titenskii. Svoistva kovkogo chuguna. Moscow, 1967.

K. P. BUNIN and A. A. BARANOV

References in periodicals archive ?
due to intensification of schedule of power supply of the graphitization furnace, fabrication of the products has increased by 15-20%.
We use artificial graphite produced through treatment at very high temperatures in our graphitization furnace at Omachi Plant, based on our proprietary powder processing technology.
But he fails to note that all of these geological samples are actually of geological graphite, so did not undergo the combustion and graphitization required for the biological samples.
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Thus, a question arises: Is it possible to fabricate composite bipolar plates with high conductivity and mechanical properties without carbonization and/or graphitization (and thus at low cost)?
An explanation for this effect might be that during LA the surface of the sample is modified not only at the ablated spot but also on the peripheral zones as a result of redeposition of ablated material and thermal modification, such as graphitization.
As a further step, a portion of the `cellulose' product from the first processing was subjected to a second round of solvent extraction before combustion and graphitization (NRC4 in TABLE 1).
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Some of our larger projects include the expansion of our fiber capacities in Inverness/Scotland and in the electrode business, the replacement of the older graphitization furnaces with the more modern length-wise graphitization furnaces in La Coruna/Spain.
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In addition, inefficient graphitization furnaces located in Meitingen/Germany and Morganton, North Carolina/USA will be closed.
Moreover, the graphitization of the carbon pyrolyzed from the modified PR is significantly promoted by HBPB, which makes certain remarkable contribution to the improvement of carbon yield.