THE SCIENCE AND TECHNOLOGY CENTER IN UKRAINE
ELECTRON BEAM TECHNOLOGY AND EQUIPMENT FOR PRODUCING
CARBON%BASED MATERIALS WITH AN AMORPHOUS,
NANO% AND MICRO%SIZED STRUCTURE
Description
Technology is based on the method of electron beam evap(cid:28)
oration of carbon (graphite) using a liquid pool of tungsten
and subsequent condensation of the vapour flow, which
was suggested by us and patented in Ukraine and the USA
(US Patent #5296274, cl. B05D 1/00 Movchan B.A. and
others. "Method of producing carbon(cid:28)containing materials
by electron beam vacuum evaporation of graphite and sub(cid:28)
sequent condensation"). Evaporation is performed as fol(cid:28)
lows: a plano(cid:28)cylindrical tungsten tablet 5–10 mm high is
placed on the end face of a cylindrical graphite block of
50–100 mm diameter and specified length. The tablet is
melted by the electron beam and forms a "hot pool". A con(cid:28)
tinuous transport process of carbon dissolution in the liq(cid:28)
uid pool volume, subsequent evaporation from the pool
surface and formation of an intensive vapour flow of car(cid:28)
bon atoms (clusters) is established. Tungsten practically
does not evaporate. Located near the above(cid:28)mentioned
carbon evaporation source is the second independent tra(cid:28)
ditional source of electron beam evaporation of metallic
and non(cid:28)metallic materials, which are added to the main
vapour flow of carbon by evaporation, if required (The
third evaporation source can also be used). This method
has been recently improved by applying the technique of
reflection of the vapour flow of carbon (or carbon plus
additives) from surfaces (mirrors) heated up to high tem(cid:28)
peratures (1000–1800°C), to form in space vapour flows of
a specified orientation and more uniform in terms of com(cid:28)
position, structure and energy of the particles. This
improvement is required at subsequent deposition of the
vapor flow and "engineering" of the specified coating
structure. Vapour flow ionization and bleeding gases into
the vacuum chamber can be used as additional technologi(cid:28)
cal parameters for controlling the deposition process and
condensate structure. Temperature of the deposition sur(cid:28)
face is one of the main technological parameters, control(cid:28)
ling the condensate structure. Rate of evaporation of a
graphite block of 70 mm diameter is equal to 1.0–1.1 kg/h.
Innovative Aspect and Main Advantages
Electron beam technology differs from the currently avail(cid:28)
able methods of arc and laser evaporation of carbon by
availability of many parameters for fine adjustment of the
main stages of the evaporation process, vapour flow forma(cid:28)
tion and its condensation, namely:
1. Area, average values of evaporation rate and tempera(cid:28)
ture of atoms (molecules) evaporated from the tungsten
"hot pool".
2. Temperature, composition and molecular structure of
the vapour flow after reflection from the heated surfaces,
vapour flow ionization, bleeding gases and using additives
of inorganic and organic substances, including catalysts of
the growth of macromolecular structures of the type of
nanotubes and fullerenes.
42
Temperature of the condensation surface of an oriented
vapour flow in the range from room temperature to
1000–1200°C and respective structures
3. from amorphous to nano(cid:28) and micro(cid:28)sized. Possibility of
producing macromolecular (fullerenes, nanotubes) and
diamondlike structures, carbides and composite materials
(coatings) on their base is shown. A pilot production elec(cid:28)
tron beam unit of up to 250 kW power adapted to the
above technology variants
is available. Areas of
Application:Electronics and optoelectronics, medicine,
chemical technology, instrument and mechanical engineer(cid:28)
ing.
Stage of Development
Technology and equipment have been patented, experi(cid:28)
mental facilities are available, and a demonstration can be
done.
Contact Details
Іnternational Center for Electron Beam Technologies of
E.O.Paton Electric Welding Institute of NASU
68, Gorky str., Kiev(cid:28)150, 03150, Ukraine
Yakovchuk Konstantin
Tel. +38 044 289(cid:28)2176Fax +38 044 287(cid:28)3166
E(cid:28)mail: yakovchuk@paton(cid:28)icebt.kiev.ua
http://www.paton(cid:28)icebt.kiev.ua
Pic. 1. Examples of special structures of carbon condensates:
nanotubes (a) and spheres (b)
SCIENCE AND INNOVATION. Special Issue, 2007
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