STUDY OF CRYSTALLIZED CASTING WORKPIECE SINTERING
PREPARED FROM LITHIUM-ALUMINUM SILICATE GLASS DRAINAGE
E. I. Suzdal’tsev
and A. S. Ermolaev
Translated from Novye Ogneupory, No. 3, pp. 119 – 122, March 2015.
Original article submitted December 13, 2014.
Results are provided for a study of crystallized casting workpiece sintering prepared from lithium-aluminum
silicate glass drainage after casting.
Keywords: glass ceramic, lithium-aluminum silicate glass (LAS-glass), density, porosity, water absorption,
x-ray phase analysis microstructure.
Currently in ONPP Tekhnologiya ceramic technology is
used for preparing objects from glass ceramics OTM-357
and OTM-357-O (main phase b-spodumene) [1 – 4]. Ac-
cording to this technology objects are prepared by slip cast-
ing in a gypsum mold. The slip is prepared from lumps of
original glass (OTM-357) and scrap of previously fired
lumps or waste after firing (OTM-357-O). Drainage waste
after casting is not used, although the weight fraction of cast-
ing drainage may reach 15% of workpiece weight depending
on object shape.
Use of previously crystallized lithium-aluminum silicate
glass (LAS) makes it possible to reduce heat treatment dura
tion from 70 to 24 – 30 h due to a higher heating rate. Since
prior crystallization of LAS glass is performed at
1170 – 1250°C for 4–8h, this requires additional use of
high-temperature firing furnaces and increases firing dura
tion of a single object to 10 h. The authors of an article 
have studied the possibility of reducing the temperature of
prior crystallization for original LAS glass in order to reduce
heat treatment duration. In addition, the possibility has been
demonstrated of using material previously crystallized at
850 – 900°C for manufacturing LAS glass workpieces,
which provides a reduction in the level of its heat treatment
temperature from 1180 – 1250 to 850 – 900°C. As a result of
this the possibility arises of performing heat treatment not in
high-temperature firing furnaces, but in low-temperature
equipment (up to 1000°C) with a reduction in heat treatment
duration in high-temperature furnaces.
More thorough study of the crystallization process of
original LAS glass in the range 850 – 900°C has been per-
formed previously. Results of these studies showed that LAS
glass specimens in this temperature range crystallize in the
Refractories and Industrial Ceramics Vol. 56, No. 2, July, 2015
1083-4877/15/05602-0160 © 2015 Springer Science+Business Media New York
OAO Obninsk Scientific-Production Enterprise Tekhnologiya,
Fig. 1. X-ray diffraction patterns of specimens heat treated at 1225,
1250, and 1275°C with holding at the final temperature from 0 to
5h:1 ) b-spodumene solid solution; 2 ) rutile; 3 ) alumotitanate (a is
with alumotitanate, b is without alumotitanate).