Microstructural Characterization and Thermal Properties of Aluminium Titanate/YSZ Ceramics

Abstract

Yttria stabilized zirconia (YSZ, with 3 mol.% Y2O3) has superior high temperature properties such as high tolerance for thermal shock, low thermal conductivity, mechanical properties, elevated melting point, good phase stability, and excellent oxidation resistance. Aluminium titanate (Al2TiO5) exhibits extremely good thermal shock resistance and low thermal conductivity coupled with good chemical resistance in molten metals. In the present work, aluminium titanate/YSZ ceramics with dierent percentages of Al2TiO5 was prepared using powder metallurgy techniques. The microstructural, mechanical and thermal properties were characterized using X-ray diraction, scanning electron microscopy, dierential scanning calorimetry, dilatometer and hardness. Thermal shock resistance behaviour under water quenching of the as-prepared ceramics was also evaluated. The results revealed that the addition of aluminium titanate to YSZ matrix improves the properties of the aluminium titanate/ YSZ ceramics.

Microstructural Characterization and Thermal Properties of Aluminium Titanate/Talc Ceramic Matrix Composites

“…Both the bulk and true densities of the composites decreased with increasing aluminium titanate content. Note that the theoretical density of calcined talc is 3.047 g cm −3 whereas the density of Al 2 TiO 5 is 3.20 g cm −3 [4,5]. Also evident in Table I is that the porosity and water absorption decreased with Al 2 TiO 5 content (from 0 to 20 wt.%) and sintering temperature.…”

Direct additive manufacturing of large-sized crack-free alumina/aluminum titanate composite ceramics by directed laser deposition

“…Al 2 TiO 5 is a ceramic characterized by low CTE, low thermal conductivity and excellent thermal shock resistance (Borrell et al, 2013;Ohya et al, 2017). As a second phase, Al 2 TiO 5 can improve the fracture toughness and the thermal properties of Al 2 O 3 because of the enhancement of the local residual stresses induced by the large mismatch of the CTE between Al 2 O 3 and Al 2 TiO 5 (Yang et al, 2009;Citak and Boyraz, 2014). It has been proved that the addition of Al 2 TiO 5 to Al 2 O 3 resulted in better flaw-tolerance properties and combined properties of both Al 2 O 3 and Al 2 TiO 5 (Padture et al, 1993;Baudin et al, 2006;Berger and Sayir, 2008).…”

Thermal Properties and Microstructural Characterization of Aluminium Titanate (Al2TiO5) / La2O3 -Stabilized Zirconia (ZrO2) Ceramics

“…Slightly higher ions e.g., those of La 3+ (ionic radius of 1,15 Å) replace the lesser ions like some of the Zr 4+ ions in the crystal matrix provides a stabilization of polymorphic tetragonal zirconia over a varied range of temperatures. Obtained the doped zirconia powders are identified as stabilized zirconia [3]. In recent years, great interest has been concentrated understanding of the superior electrical, chemical and mechanical properties such as thermal, fracture toughness and strength like high tolerance for thermal shock and low thermal conductivity of Lanthana stabilized zirconia [8][9][10][11][12][13][14].…”

“…As a synthetic ceramic, Aluminum titanate (Al2TiO5) is the most widely used as structural materials due to their low thermal conductivity, good thermal shock resistance and great melting point. Even though aluminium titanate is a popular material, it has specific disadvantages such as inter granular micro cracking, which exhibits due to the great thermal anisotropy of singular particles, that greatly limits the mechanical properties of polycrystalline Al2TiO5 [3]. Aluminium titanate (Al2TiO5) is usually prepared by several procedures.…”

“…The monoclinic phase exists at the room temperature and the temperatures greater than 1170 °C it transforms to the tetragonal form. The tetragonal phase is constant at temperatures of 1170 -2370 o C, and the cubic phase occurs at over 2370 °C [1][2][3][4][5][6][7]. The transition from tetragonal form to monoclinic phase (about 9%) undergoes large volume change in microstructure which makes difficult to obtain stable sintered zirconia ceramic products.…”