SILICIDE CERAMIC SYNTHESIS BASED ON MOLYBDENUM DISILICIDE
IN A COMBUSTION REGIME UNDER HIGH-TEMPERATURE
A. M. Stolin,
P. M. Bazhin,
M. V. Mikheev,
M. R. Filonov,
and D. V. Kuznetsov
Translated from Novye Ogneupory, No. 6, pp. 56 – 61, June 2015.
Original article submitted February 27, 2015.
A fundamental possibility is demonstrated of using SHS-extrusion and SHS-compression methods, combin
ing combustion and high-temperature deformation, for preparing compact materials and objects of silicide ce
ramics based on MoSi
. Formability of silicide ceramic by free SHS-compression is studied. The effect of
holding time before high-temperature deformation, heating temperature, and metal binder content in an origi
nal charge workpiece, on the degree of synthesized material deformation is studied. Specimen macro- and
microstructure, prepared by SHS-extrusion is provided, and the effect of high-temperature heating on specific
electrical resistance is also studied.
Keywords: SHS-extrusion, SHS-compression, high-temperature deformation, silicide ceramic, molybdenum
A promising method for preparing silicide ceramics is
self-propagating high-temperature synthesis (SHS). The SHS
method is based on using starting component internal energy.
A feature of the method concerns the fact that occurrence of
a self-propagating reaction is possible within a narrow zone,
which moves throughout a whole substance due to heat
transfer after local short-term initiation in the original re
agent mixture .
Among silicide ceramics the most widespread is made of
molybdenum disilicide MoSi
. It has low electrical resistance
(170 – 200 mW·cm), resistance in oxidizing atmospheres (up
to 1700°C), molten metals and salts. Materials based on mo
lybdenum disilicide are currently most promising taking ac
count of the level of their high-temperature properties of
creep and crack resistance [2, 3]. High-temperature heating
elements (HHE) used in electric resistance furnaces for heat-
ing up to 1700°C [4, 5] are manufactured from material
based on molybdenum disilicide. In order to improve creep
resistance these materials are alloyed with niobium, tung-
sten, boron, etc. [6, 7], although this leads to a reduction in
crack resistance . Balancing these specifications is
achieved by introducing refractory metal silicides and oxides
into the alloy, and the combination of different silicides 
and other alloying additions  is important.
A little studied, but promising problem is preparation of
compact objects made of silicide ceramic under conditions of
combustion with high-temperature deformation under the ef
fect of external mechanical action. This combination is im
plemented in SHS-extrusion and SHS-compression methods
[10, 11], within which material is subjected to shear defor
mation. The possibility of the method is based on the capac
ity of a hot mix of synthesized product for macroscopic flow.
For SHS materials this deformation may only be accom
plished in a characteristic temperature range (processing
range) from the combustion temperature (1900°C) to the via
bility temperature (1750°C) above which the material exhib
its a capacity for plastic deformation, but below this it solidi
fies and loses its ductile properties. The capacity for
high-temperature macroscopic flow depends both on rheo
logical property level (yield strength, shear and volumetric
Refractories and Industrial Ceramics Vol. 56, No. 3, September, 2015
1083-4877/15/05603-0304 © 2015 Springer Science+Business Media New York
Proceedings of the International Conference of Refractory
Workers and Metallurgists (19 – 20 March 2015, Moscow).
FGBUN Institute of Structural Macrokinetics and materials sci
ence problems, Russian Academy of Sciences, Chernogolovka,
Moscow Region, Russia.
FGAOU VPO National Research Technology University
(MISiS), Moscow, Russia.