Effect of Aluminum Titanate Additives on Crystal Structure Parameters and Sintering of Zirconium Dioxide
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Vol. 61, No. 3, September, 2020
EFFECT OF ALUMINUM TITANATE ADDITIVES ON CRYSTAL STRUCTURE PARAMETERS AND SINTERING OF ZIRCONIUM DIOXIDE M. I. Tenevich,1,2,3 A. P. Shevchik,1 and V. N. Fishchev1 Translated from Novye Ogneupory, No. 5, pp. 29 – 34, May, 2020.
Original article submitted April 7, 2020. Monoclinic zirconium dioxide compositions of formula ZrO2–Al2TiO5 containing 0, 2, and 3.5% Al2TiO5 are studied. The aim of the research is to study the effect of aluminum titanate additives on the parameters of the monoclinic zirconium dioxide crystal lattice and sintering of the resulting product. The formation of a solid solution of aluminum titanate in monoclinic zirconium dioxide is confirmed using SEM and x-ray phase analysis. Sintered products are made from monoclinic zirconium dioxide with aluminum titanate additives as a proof of concept. Keywords: zirconium dioxide, aluminum titanate, solid solutions, solid-state synthesis.
metal-resistance so that it is widely used as a refractory. The high electrical conductivity of ZrO2 above 1000°C allows it to be used as a high-temperature conductor and heating element. ZrO2 can be used in reactor construction because of its nuclear properties [3]. Polymorphism is a characteristic property of ZrO2, which can exist in three crystalline modifications: monoclinic, tetragonal, and cubic. In nature, ZrO2 is found in the monoclinic a-modification of density 5.56 g/cm3. The structure of the monoclinic modification is a deformed fluorite structure. The monoclinic form transitions at 950 – 1200°C into the tetragonal form of density 6.10 g/cm3, which is also a deformed fluorite structure. The tetragonal form transitions at 2300°C into the cubic form of density 6.27 g/cm3 with the CaF2 structure, which persists until melting [2].
INTRODUCTION The phases forming the ZrO2–Al2TiO5 system are a partial cross-section of the ternary Al2O3–ZrO2–TiO2 system, coexist with each other [1], and possess several unique properties that enable the formulation of high-temperature innovative compositions based on them. The only stable compound in the Zr–O system is ZrO2. The melting point of pure ZrO2 is 2715°C; boiling point, 4300°C [2]. ZrO2 is characteristically chemically inert to acids and bases and has relatively high mechanical strength, low thermal conductivity, and elevated glass-, slag-, and 1 2 3
St. Petersburg State Technological Institute (Technical University), St. Petersburg Russia. Ioffe Institute, St. Petersburg, Russia. [email protected]
TABLE 1. Crystal Lattice Parameters of ZrO2 Modifications a, Å
b, Å
c, Å
V, Å2
T, °C
Reference
5.1
5.2
5.3
—
25
[4]
5.1471
5.2125
5.3129
—
25
PDF000-37-1484
5.1505
5.2116
5.3173
140.88
25
ICSD 1002078
t-ZrO2
3.64
—
5.27
—
25
[4]
c-ZrO2
—
—
5.26
—
2330
[4]
Modification
m-ZrO2
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M. I. Tenevich, A. P. Shevchik, and V. N. Fishchev
TABLE 2. TCLE (a) of ZrO2 Modifications Modification
m-ZrO2 t-ZrO2 c-ZrO2
a,
10–6
K–1 T, °C
Refer
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