Characterization of composites containing NiAl2O4 spinel phase from Al2O3/NiO and Al2O3/Ni systems

Abstract

This paper focused on the characterization of the composites containing nickel aluminate spinel from Al 2 O 3 /NiO and Al 2 O 3 /Ni systems. The composites were prepared by die pressing of powders and subsequent sintering of green bodies in air atmosphere. Composites were characterized by XRD, SEM, EDS and DTA/TG/MS analyses. The physical properties of the composites were measured by Archimedes method. Quantitative description of the composites microstructure was made on the basis of SEM images using computer image analysis. The XRD studies and SEM observations of composites confirmed the presence of two phases Al 2 O 3 and NiAl 2 O 4 in the whole volume of samples from both systems. Spinel phase was evenly distributed throughout the volume of the material. Morphology of NiAl 2 O 4 obtained from both systems was characterized by the presence of voids. The DTA/TG/MS measurements showed the characteristics of organic binder decomposition and type of gases released to the atmosphere during thermal treatment. Moreover, the DTA/TG analysis showed the temperature of spinel-phase formation for both systems. It was found that the spinel-phase NiAl 2 O 4 formation retards the process of densification. Therefore, it can be concluded that densification of samples with spinel phase depends mainly on the volume of spinel phase in composite material and does not depend on the substrates used to prepare spinel phase. The values of the selected properties of Al 2 O 3 -Ni-and Al 2 O 3 -NiO-based materials confirmed that the physical properties depend on the type of substrates used in the fabrication of composites. The type of powder influences the open porosity of samples. For composites produced using NiO powder, open porosity is lower than for samples formed with nickel powder.

Producing carbon nanotubes from thermochemical conversion of waste plastics using Ni/ceramic based catalyst

“…NiO peaks appear at 63° and 76°, respectively, for the catalyst with different Ni contents loadings [14]. Two NiAl2O4 peaks appear at around 173 37° and 77° [38]. ICP results as shown in Table 1 further indicate that the content of 174 correlating with metal loading, in agreement with the literature [11], resulting in average particle size of 35.2 ± 3.5 nm for the 2.0/ceramic (Fig.3 D).…”

Thermoanalytical studies of the ceramic-metal composites obtained by gel-centrifugal casting

“…The mass loss at lower temperatures is connected with thermal decomposition of organic additives used in gel-centrifugal casting, mainly poly(glycerol monoacrylate). However, the mass increase can be ascribed to the oxidation of Ni as described elsewhere [35]. The mass spectrometer has detected five m/z values: 18, 44, 45, 46, and 52.…”

Effect of Aluminum Titanate (Al2TiO5) Doping on the Mechanical Performance of Solid Oxide Fuel Cell Ni‐YSZ Anode

“…In the presented manufacturing conditions, ALT spontaneously decomposes to Al 2 O 3 and TiO 2 , , . Part of the Al 2 O 3 initially reacts with NiO to form NiAl 2 O 4 , , , , proportionally to the amount of Al 2 O 3 made available through ALT doping. For the oxidized samples, an enhancement of the scaled characteristic strength was observed for all of the ALT doping amounts.…”