SCIENTIFIC RESEARCH AND DEVELOPMENT
PREPARATION OF HIGHLY CONCENTRATED BINDER SUSPENSIONS
BASED ON MAGNESIUM ALUMINUM SILICATE GLASS
E. I. Suzdal’tsev,
T. V. Zaichuk,
Yu. S. Ustinova,
and S. N. Vandrai
Translated from Novye Ogneupory, No. 11, pp. 29 – 33, November 2015.
Original article submitted April 28, 2015.
Wet milling in a ball mill is used to prepare a suspension based on amorphous and crystallized magnesium alu
minum silicate glass. The stabilizing additives used are hydrochloric and oxalic acids, and also an aqueous
ammonia solution. Raw material is molded by slip casting in porous molds. Optimum ranges are provided for
magnesium aluminum silicate glass suspension casting parameters in order to prepare green workpieces with
not more than 30% porosity.
Keywords: glass ceramic, highly concentrated ceramic binder suspension (HCBS), slip, magnesium alumi-
num silicate glass, cordierite, ionic potential (IP), particle size distribution.
Glass ceramic materials are in demand in the space and
aviation branches of industry as materials for preparing an-
tenna radomes for rockets of different classes. A number of
specifications are laid down for radioparent domes apart
from radio engineering properties (low value of dielectric
permittivity and dielectric loss angle) providing protection of
radio equipment from external action: thermal shock resis
tance, refractoriness, and low LTEC . The magnesium alu
minum silicate system is promising for creating glass ce
ramic material based upon it satisfying these specifications,
whose main crystalline phase is cordierite.
The aim of this work is preparation of highly concen
trated ceramic binder suspensions (HCBS) based on magne
sium aluminosilicate glass suitable for molding workpieces
by slip casting in porous molds in order to prepare dense
pore-free glass ceramic material of cordierite composition.
Glass ceramic materials were first studied by Stookey in ex
amining processes of photosensitive glass crystallization .
Newly developed material pyroceram was prepared from
glass by crystallization by a special regime. The material ex
hibited good thermal shock resistance, improved mechanical,
electrical, and other properties .
One of the most well-known glass ceramic materials is
pyroceram 9606 . This is glass ceramic of the magnesium
aluminosilicate system with titanium dioxide as a catalyst.
The main phase is cordierite and provides low dielectric
losses, good thermal shock resistance, and strength, and also
resistance to climatic effects. Porosity is absent from the ma-
terial, and it is resistant to a high moisture content even with-
out use of coatings.
Various methods are well known for preparing cordierite
ceramic: crystallization from glass, growing single crystals
from fluxes, sol-gel technology, solid-phase synthesis from
oxides or from natural materials . Slip casting is one of the
most widespread methods for molding ceramic materials
making it possible to prepare objects of any shape with suffi
ciently uniform distribution of material properties through
out the volume. During subsequent heat treatment there are
physicochemical processes of sintering and (or) crystalliza
tion, and a material acquires prescribed properties .
On the basis of technology developed for preparing mag
nesium aluminosilicate glass slip general principles have
been proposed for the technology of HCBS preparation, in
cluding starting material refinement, combining it with a dis
persion medium, and stabilization with electrolytes by means
of controlling pH and mechanical mixing. Mineral particles
within a slip absorb and strongly hold a thin water film at
their surface. The thickness of water shells depends on parti
cle fineness and their electrical charge, and is important tech
nologically. The amount of water shell may be regulated by
introducing electrolytes whose cations replace cations of ad
Refractories and Industrial Ceramics Vol. 56, No. 6, March, 2016
1083-4877/16/05606-0601 © 2016 Springer Science+Business Media New York
OAO ONPP Tekhnologiya, Obninsk, Kaluga Region, Russia.