Search

This research study investigates the potential use of traditional raw materials to synthesize new ceramic composite materials that can be used in different industrial applications. The composite materials were developed through mechanical activation, carbonization, and reactive sintering techniques. Natural zeolite from Tokaj region, alumina from Motim, and sawdust were used as starting raw materials. Stoichiometric amounts of the raw materials were mixed and milled in planetary ball milling followed by uniaxially pressing to produce cylindrical ceramic discs. The produced green ceramics were then sintered in an electric laboratory kiln under an oxygen-free environment at 1200 °C. In-situ carbonization of the sawdust was confirmed via X-ray diffraction. The thermal properties were also investigated by derivatography. The produced ceramic specimens were tested on microstructural characteristics, porosity, density, and water absorption. [ABSTRACT FROM AUTHOR]

In this research work, new zeolite-alumina composite materials were prepared by mechanical activation and reactive sintering method. A detailed investigation of structure and microstructure of the raw materials and the produced ceramic samples have been precisely examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Based on the raw material compositions, microstructure, and firing temperature, different characteristics were examined including, density, shrinkage, porosity and water absorption. The authors have found that the compositions and the firing temperature play a major role in the microstructure and the properties of the final product. [ABSTRACT FROM AUTHOR]

In this research work, the possibilities of producing advanced ceramics from traditional, relatively inexpensive raw materials were studied. Powder mixtures from kaolinite and IG-017 bio-original additive were milled and uniaxially pressed to pellets, then pre-sintered in the electric kiln under oxidation and oxygen-free atmosphere at 1250°C. The pre-sintered specimens were then further sintered in nitrogen gas at 1600°C. The produced specimens were tested on composition, microstructures and morphologies using several characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDAX). The conducted experiments by the authors have shown that it is possible from traditional kaolinite to develop technical ceramic specimens with increased physical and mechanical properties based on formed amorphous phases, mullite crystals, micro and nano carbon fibers. [ABSTRACT FROM AUTHOR]

Hetero-modulus, hetero-viscous complex materials have several advantages in accordance to mechanical and thermal properties comparing with the traditional ceramics and ceramic matrix composites. In this paper the authors examined in details the high speed collision processes between flying metallic objects and ceramics, such as α-Si3N4, β-Si3N4, Si2ON2, SiAlON, AlN and 3Al2O32SiO2 reinforced alumina matrix hybrid materials, as well as their rheo-mechanical structures and properties. Understanding the high speed collision process, material structures, rheological properties of such a complex hybrid material, the authors in this paper mathematically describe the mechanical shear stress and its relaxation during and after high speed collisions in α-Si3N4, β-Si3N4, Si2ON2, SiAlON, AlN and 3Al2O32SiO2 reinforced alumina matrix composites. The dynamic strength of the developed and examined corundum matrix complex materials was tested through collision with high density metallic flying bodies, with speed higher than 900 m/sec and described in works [27, 29, 42]. Analytical methods applied in this research were scanning electron microscopy, X-ray diffraction and energy dispersive spectrometry. Digital image analysis was applied to microscopy results, to enhance the results of transformation. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the guest editors features the diverse applications of ceramic materials in Hungary and Russia.