Compressive creep of mullite containing Y2O3

Microstructure and high temperature 4-point bending creep of sol–gel derived mullite ceramics

“…Studying the creep behavior of mullite/alumina fibres, Deléglise et al 28 attributed the stress exponent n = 2 to a higher viscosity of thin amorphous alumino-silicate intergranular glassy phase. De Arrelanno-López et al 19 believe that large variations in Q values reported in literature and very different interpretations of creep mechanism could, at least partially, be related to grain morphology, as well as, to composition and location of the glassy phase.…”

“…1 Creep of mullite has been investigated for the last three decades. Works have been performed in bending, [2][3][4][5][6][7][8][9][10][11][12][13] in compression 11,[14][15][16][17][18][19] and in tension. 11 Materials with different microstructures and compositions ranging from 67 to 82 wt.% of alumina and a wide range of activation energies (Q ∼ 357−1051 kJ/mol), stress exponents (n ∼ 0.2-2.7) and grain size exponents (p ∼ 1-3.7) have been characterized in experiments from 0.2 to 300 MPa and temperatures from 1100 to 1500 • C. There is no universally accepted opinion about the mechanism of the creep.…”

Evaluation of the Influence of MgO and La2O3 on the Fast Sintering of Mullite

“…Therefore, studies on the use of sintering aids to enhance the densification and sintering kinetics and lower the sintering temperature of mullite bodies are very important in order to produce high-strength low-cost bodies 6 . The role of sintering additives has been attributed to the formation of liquid phase and to a reduction in viscosity of the glassy (or liquid) phase or to a reduction in mullite formation temperature in gel-derived powders, thereby leading to higher mobility of diffusing species [7][8][9][10][11] . Reports in the literature on studies involving mullite have focused on the nucleation of gel-derived mullites and doped mullites 5,7,[12][13][14][15][16] and on the conventional sintering of mullite compacts [17][18][19][20] .…”

Cost-effective macro-porous mullite-corundum ceramic membrane supports derived from the industrial grade powder

“…As promising structural materials, mullite (3Al 2 O 3 ·2SiO 2 ) and mullite-based ceramics have been studied considerably in last decades for its interesting properties such as relatively low thermal expansion co-efficient, low specific gravity, high creep resistance, low thermal conductivity, good infrared transparency and low dielectric constant [13,14]. Due to low thermal expansion co-efficient, mullite-based ceramics with good thermal shock resistance are widely applied at high-temperature thermal cycling environments.…”