EFFECT OF ORIGINAL POWDER MIXTURE FRACTIONAL COMPOSITION
AND DISPERSION ON REACTION-BONDED SILICON CARBIDE
E. S. Antonova,
N. A. Golubeva,
I. Yu. Kelina,
L. A. Plyasunkova,
T. E. Stakhrovskaya,
and A. S. Nechepurenko
Translated from Novye Ogneupory, No. 10, pp. 37 – 41, October 2014.
Original article submitted September 9, 2014.
Results are given for an experimental study of the effect of fraction composition and dispersion of an original
charge on the main domestic silicon carbide polydispersed powders developed by OAO UNIKhIM with a Test
Plant on ceramic physicomechanical properties prepared by reaction sintering.
Keywords: silicon carbide, reaction sintering, fractional composition, powder mixture, structure, physico-
Ceramic materials OTM-923 and OMK-927 have been
developed in ONPP Tekhnologiya, prepared by reaction
sintering of silicon carbide powder from the Zaporozhe
Abrasive Plant. Materials are distinguished by high hardness
and ultimate strength in bending of 150 – 300 MPa . Re
action sintering technology makes it possible to prepare ob
jects with the minimum machining tolerance, and production
equipment for implementing reaction sintering has a lower
energy content and is more accessible compared with, for ex
ample, hot pressing. Reaction sintering proceeds at lower
temperature, and makes it possible to use cheaper and
coarser powders. The method has a wide choice of molding
procedures for workpieces, and the materials obtained ex
hibit properties close to hot-pressed. This gives rise to advan
tages in the production of large objects and components for
which diffusion sintering is ineffective.
By the resolving the problem of import substitution
within the scope of federal target programs OAO UNIKhIM
with a Test Plant has developed a carbothermal method for
polydispersed silicon carbide powder. The powder is distin
guished by high purity with a prescribed grain size. We have
studied the effect of fraction composition and original charge
fineness based on silicon carbide powder of domestic pro-
duction on achieving good physicomechanical property indi-
ces for reaction sintered silicon carbide.
In order to prepare charges silicon carbide powder of
green grade 63 S with grain size F 150, F 180, F 220, F 320,
F 500, F 1200, and carbon black grade P-803 with a specific
surface of 30,000 cm
/g were used. Shape and condition of
the SiC powder particle surface is imperfect and particles
have a lumpy shape (Fig. 1), since they are prepared by
crushing followed by classification. According to sedimenta
tion analysis data the SiC powder grain size composition en
tirely corresponds to GOST 3647, and the proportion of the
main fraction is more than 50% (Table 1).
According to data of the powder developers, in all frac
tions the content of the main SiC phase is 96.0 – 96.3%, and
Fe impurity, reducing high-temperature strength, is not more
than 0.5% (Table 2).
In order to prepare experimental specimens of silicon
carbide powder of different grain size composition they were
mixed with powder of a carbon-contaning component in the
Refractories and Industrial Ceramics Vol. 55, No. 5, January, 2015
1083-4877/15/05505-0409 © 2015 Springer Science+Business Media New York
GNTs RF OAO Obninsk Scientific Production Enterprise
(ONPP) Tekhnologiya, Obninsk, Kaluga Region, Russia.
OAO UNIKhIM with a Test Plant, Ekaterinburg, Russia.