Sintering and characterization of aluminum titanate ceramics with enhanced thermomechanical properties

Abstract

Aluminum titanate (Al2TiO5) was synthesized from Al2O3‐TiO2 system by solid‐phase reaction with additives of light magnesium carbonate and SiO2, incorporating with silicon carbide (SiC) particle. The influence of additives on the phase composition, microstructure configuration, sintering, and thermomechanical properties of the developed materials was investigated. The experimental results illustrated that the utilization of additives with applicable contents was conducive to the development of complex microstructures. The microstructures characterized by microcracks matrix together with interlocked grains were identified. The samples incorporating SiC and SiO2 simultaneously displayed exceptional densification properties and microstructure as a result of a SiO2 liquid phase accelerating SiC oxidation. Meanwhile, high flexural strength (41.51 MPa) and low thermal expansion coefficient of 0.485 × 10−6 K−1 (RT‐1000 °C) were detected, encouraging refractory applications with high thermomechanical solicitations.

Remarkable Structural Modifications of Tialite Solid Solutions Obtained by Different Methods

“…This observation suggests that the sintered polycrystal may exhibit low strength. The problem of improving the mechanical parameters of tialite-made polycrystals is now widely discussed in the literature [ 20 , 21 , 27 ].…”

“…Tialite is characterized by the high anisotropy of its thermal expansion coefficients [ 5 ]. As a result of the formation of a complex stress state in the material, micro and macro cracks are formed in the material during its cooling after reaction sintering [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. These cracks provide desirable properties, such as a low macroscopic thermal expansion coefficient [ 22 ], low thermal conductivity [ 23 , 24 , 25 ], and, thus, high resistance to thermal shock [ 1 , 11 , 26 , 27 ].…”

“…Tialite also has high resistance to microcrack propagation [ 28 ]. The micro and macro cracks present in the material reduce its flexural strength [ 20 , 29 , 30 ] and its values for Young’s modulus and Poisson’s number [ 31 ]. Therefore, it is necessary to optimize the reactive sintering process and to select stabilizing additives in order to obtain a material characterized by the optimum size and number of micro-cracks, due to which it will have a characteristic resistance to thermal shock while maintaining its mechanical properties.…”

Thermodynamic properties of aluminum titanate‐mullite composite ceramics containing heat stabilizer

“…Aluminum titanate (AT) ceramic is a synthetic ceramic material, which is formed by the solid phase reaction of equimolar ratio Al 2 O 3 and TiO 2 . Aluminum titanate ceramic has excellent physical and chemical properties, such as low thermal expansion coefficient (∼1 × 10 −6 K −1 ), 1,2 low thermal conductivity (1.5–2.5 W⋅(m⋅K) −1 ), 3,4 high thermal shock resistance (500 Wm −1 ), 5 high melting point (∼1860°C), 6–8 high temperature resistance (can work for a long time at 1400°C), good corrosion resistance (resistance to refractory metals such as copper, aluminum water, molten iron) 9,10 . Because of above excellent properties, it has a broad application prospect as a structural ceramic in the field of high temperature, such as, refractories for the molten aluminum alloy industry, 11,12 diesel particulate filters, 13 automobile exhaust purification catalyst carriers 1,7 …”