
Thermomechanical properties of mullitic materials
Author(s) -
Jan Urbánek,
Jiří Hamáček,
Jan Macháček,
Jaroslav Kutzendörfer,
Jana Hubálková
Publication year - 2017
Publication title -
processing and application of ceramics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.326
H-Index - 15
eISSN - 2406-1034
pISSN - 1820-6131
DOI - 10.2298/pac1704322u
Subject(s) - flexural strength , materials science , composite material , ceramic , flexural modulus , deflection (physics) , modulus , material properties , three point flexural test , young's modulus , physics , optics
Mechanical tests provide important information about the properties and behaviour of materials. Basic tests include the measurement of flexural strength and in case of refractory materials, the measurement of flexural strength at high temperatures as well. The dependence of flexural strength on the temperature of ceramic materials usually exhibits a constant progression up to a certain temperature, where the material starts to melt and so the curve begins to decline. However, it was discovered that ceramic mullitic material with a 63 wt.% of Al2O3 exhibits a relatively significant maximum level of flexural strength at about 1000 °C and refractory mullitic material with a 60 wt.% of Al2O3 also exhibits a similar maximum level at about 1100 °C. The mentioned maximum is easily reproducible, but it has no connection with the usual changes in structure of material during heating. The maximum was also identified by another measurement, for example from the progression of the dynamic Young’s modulus or from deflection curves. The aim of this work was to analyse and explain the reason for the flexural strength maximum of mullitic materials at high temperatures