Synthesis, Densification, and Phase Evolution Studies of Al₂O₃–Al₂TiO₅–TiO₂ Nanocomposites and Measurement of Their Electrical Properties

Abstract

Alumina–aluminum titanate–titania (Al2O3–Al2TiO5–TiO2) nanocomposites were synthesized using alkoxide precursor solutions. Thermal analysis provided information on phase evolution from the as‐synthesized gel with an increase in temperature. Calcination at 700°C led to the formation of an Al2O3–TiO2 nanocomposite, while at a higher temperature (1300°C) an Al2O3–Al2TiO5–TiO2 nanocomposite was formed. The nanocomposites were uniaxially compacted and sintered in a pressureless environment in air to study the densification behavior, grain growth, and phase evolution. The effects of nanosize particles on the crystal structure and densification of the nanocomposite have been discussed. The sintered nanocomposite structures were also characterized for dielectric properties.

Alumina–titania ceramics prepared by microwave sintering and conventional pressure-less sintering

“…On the other hand, many researches showed that grain refinement in alumina ceramics led to improved properties [10][11][12][13][14]. Fine-grained alumina matrix ceramics were considerably investigated and reported to possess superior properties compared to their conventional coarse-grained counterparts [15][16][17].…”

Formation, Phase Stability, and Characterization of Unstabilized Aluminum Titanate (Al2TiO5) Ceramics

“…The samples exhibited the maximum bulk density and minimum apparent porosity during sintering at 1300°C. Traditional Al 2 TiO 5 preparation techniques, such as reaction sintering of mechanically alloyed starting materials and solid-state reaction preparation routes, produce Al 2 TiO 5 at high temperatures ranging between 1400°C and 1500°C [23,24]. In the present study, the use of the sol-gel technique to prepare Al 2 TiO 5 powder enabled the production of nanosized powder, which in turn enhanced the densi cation of the produced bodies at a low sintering temperature of 1300°C.…”

In situ alumina/aluminum titanate bulk ceramic composites prepared by SPS from different structured composite powders

“…And several investigations showed that a smaller grain size (grain refinement) in alumina ceramics led to improved mechanical properties [5,[18][19][20][21][22]. The mechanical strength of Al 2 TiO 5 ceramics also increased as the grain size decreased [23].…”