INDUSTRIAL TECHNOLOGY BASED ON SELF-PROPAGATING
HIGH-TEMPERATURE SYNTHESIS (SHS)
E. N. Il’in
Translated from Novye Ogneupory, No. 1, pp. 10 – 12, January, 2010.
Original article submitted October 19, 2009.
Characteristics of ceramic filters that are widespread in casting production practice are compared with tita
nium carbide FKT filters prepared by SHS. The advantages of FKT filters are demonstrated. Technology for
preparing new highly refractory and heat and wear-resistant materials with improved universal properties and
their fields of application are considered.
Keywords: SHS, ceramic filter FKT, titanium carbide, casting production.
OOO Termosintez is concerned with the development of
industrial technology based on self-propagating high-temper-
ature synthesis (SHS) and the production of pressed ceramic
filters FKT based on modified titanium carbide TiC (RF pat-
FOR CASTING PRODUCTION
A problem in the field of casting production is special
and steel casting. Non-metallic inclusions, always present in
molten metal, cause such casting defects as slag and gas
sinks, gas porosity, etc., that reduce casting quality and me-
chanical properties. Procedures for removing surface slag in
clusions from finished billets are very complicated and make
their treatment more expensive. Use of ceramic filters in the
majority of cases makes it possible to exclude entirely scrap
due to nonmetallic inclusions and surface defects. Currently
almost no casting production operates without using ceramic
filters. Ceramic filters are used extensively in casting pro
duction. Nonetheless, filters offered on the market are not ca
pable of resolving a number of quite serious problems, that is
connected mainly with the technology of their production.
Use of another technology, not assimilated either in Europe
or in China, has made it possible to resolve this problem.
Three main types of filters are used: foam-ceramic, ex
truded ceramic and pressed ceramic.
Foam-ceramic filters (FCF) are produced by impreg
nating openly-porous prolon with an aqueous suspension of
ceramic powder followed by drying and firing. Among the
main advantages of FCF is the possibility of varying over
wide limits the porosity and maximum capacity compared
with other types of filters to hold back nonmetallic inclu
sions. The disadvantages are: a rapid reduction in passing ca
pacity, formation of metal splashes, and also low mechanical
strength, particularly under conditions of high-temperature
steel casting. The low mechanical strength is the main limita-
tion of using filters during casting of large ingots.
Extruded ceramic filters (ECF) are most widespread in
casting production practice. They are prepared by pressing a
moist ceramic mix through special dies followed by rapid
drying and firing. This relates to straight-through feed filters.
They exhibit greater mechanical than FCF filters, The filtra-
tion efficiency through ECF filters is somewhat lower than
for FCF filters, although they form a stable uniform laminar
flow of metal after the filter. Use of ECF filters is limited to
casting nonferrous metals and cast iron. For steel casting
these filters are not used due to a short life.
Pressed ceramic filters (PressCF) also relate to straight-
through feed filters. They are prepared by compacting a
moist ceramic mix followed by drying and firing. Among all
of the types of ceramic filters they exhibit the highest me
chanical strength. They demonstrate somewhat worse capac
ity towards holding back nonmetallic inclusions than FCF
filters, but they are better than ECF filters. Steady laminar
flow of metal forms after a filter, which facilitates a reduc
tion in casting scrap with respect to defects connected with
metal oxidation in a casting system (oxide inclusions, films)
and also scrap due to cold laps, poor joints and gas porosity,
The filters are used for all types of casting, including steel
Thus, two competing types of ceramic filters in casting
production have their own pluses and minuses. FCF filters
may be used effectively for fine filtration of metals, includ
ing steel casting of small ingots. PressCF filters are some
what worse in holding back nonmetallic inclusions, although
they are more effective than FCF filters, they reduce casting
scrap, connected with oxidation of metal in casting systems
Refractories and Industrial Ceramics Vol. 51, No. 1, 2010
1083-4877/10/5101-0012 © 2010 Springer Science+Business Media, Inc.
OOO Termosintez, Chelyabinsk, Russia.