NEW CERAMIC MATERIAL STRUCTURE AND PHASE COMPOSITION
A. D. Shlyapin,
A. Yu. Omarov,
and Yu. G. Trifonov
Translated from Novye Ogneupory, No. 12, pp. 31 – 34, December, 2012.
Original article submitted September 7, 2012.
Scanning electron microscopy and x-ray-phase analysis are used to study the structure and phase composition
of ceramic materials sintered from powders prepared by chemical dispersion of commercial grade aluminum
and silumin AK7. Results obtained are compared with specimen structure and properties from industrially
produced aluminum oxide prepared by the Bayer method (Al
O — GOST 11841–76). A zonal sintering
method is proposed on the basis of results obtained, providing formation of so-called bimodal porosity.
Keywords: aluminum oxide, corundum, scanning electron microscope, x-ray-phase analysis, bimodal
Recently ceramics have given rise to increased interest as
a fundamentally new class of materials. An advantage of ce-
ramic materials compared with metals and high-molecular
compounds is a capacity for prolonged operation under ele-
vated temperature and corrosion conditions without signifi-
cant degradation of mechanical properties, and this makes
ceramics unique heat insulating, structural, and filter materials.
This article is devoted to a study of the structure and
phase formation of ceramic materials prepared from nano
dispersed powders , giving physicomechanical property
indices. A feature of these materials is the fact that they are
prepared suing standard available equipment and with use of
normal production operations adopted in ceramic technology.
SCANNING ELECTRON MICROSCOPY
Analysis of the fracture surface of three specimens (frac
tures obtained after testing specimen in a pendulum impact
machine) were studied by means of a Karl Zeiss EVO 50
scanning electron microscope. Specimen 1 was prepared
from aluminum hydroxide of chemically pure industrial
product classification; specimen 2 was prepared from alumi
num hydroxide synthesized by breakdown of aluminum with
alkali; specimen 3 was prepared from aluminum hydroxide
synthesized by breakdown of silumin with alkali.
Refractories and Industrial Ceramics Vol. 53, No. 6, March, 2013
1083-4877/13/05306-0391 © 2013 Springer Science+Business Media New York
Fig. 1. Ceramic material structure prepared from industrial alumi
num oxide powder (a, b ).
Moscow State Industrial University, Moscow, Russia.