The discovery of (BaxCa1-x)(ZryTi1-x)O3 lead-free ceramics drawn a lot of attention to those novel materials because of their excellent piezoelectric properties. However, quite a little attention has been paid to other features of the material. This article reports a wide range of research, including composition, structure and microstructure, dielectric response and impedance spectroscopy in order to systematize and expand knowledge about this peculiar ceramics and strontium doping effect on its properties. In order to test that influence a series of samples with various strontium concentration, precisely the admixtures of 0.02, 0.04 and 0.06 mol% were prepared, as well as basic ceramics to compare obtained results.

The role of slag in the process of continuous casting of steel (CCS) is reduced to the thermal and chemical insulation of the liquid steel surface, and additionally to refining. The ability to adsorb non-metallic inclusions flowing off from the crystallizer, mainly Al2O3, determines its physicochemical properties. As a result of adsorption and dissolution of inclusions tin he liquid layer the viscosity and thickness of mould flux change, which eventually affects the technological parameters and behavior of slag in the crystallizer. The influence of aluminum oxide on the viscosity of slag was empirically investigated with a structural viscosity model worked out by Nakamoto. The results of the simulation are presented in the form of plots. Authors observed a significant influence of Al2O3 on the slag viscosity, which suggests that this effect should be taken into account when selecting chemical composition of mould flux for definite types of steel. The results of calculations also show that the disturbances in casting caused by the use of the mould slag may be connected with the content of non-metallic inclusions in steel.

In this work, three ceramic composite coatings Al2O3-3TiO2 C, Al2O3-13TiO2 C, and Al2O3-13TiO2 N were plasma sprayed on steel substrates. They were deposited with two conventional powders differing the volume fraction of TiO2 and nanostructured powder. The mechanical and tribological properties of the coatings were investigated and compared. The increase in TiO2 content from 3 wt.% to 13 wt.% in the conventional feedstock improved the mechanical properties and abrasion resistance of coatings. However, the size of the used powder grains had a much stronger influence on the properties of deposited coatings than the content of the titania phase. The Al2O3-13TiO2 coating obtained from nanostructured powder revealed significantly better properties than that plasma sprayed using conventional powder, i.e. 22% higher microhardness, 19% lower friction coefficient, and over twice as good abrasive wear resistance. In turn, the Al2O3-13TiO2 conventional coating showed an increase in microhardness and abrasive wear resistance, 36% and 43%, respectively, and 6% higher coefficient of friction compared to the Al2O3-3TiO2 conventional coating.

The current study were performed in order to assess the fabrication possibility of the metal-ceramic composites based on nanocrystalline substrates. The influence of the variable time of the high energy ball-milling (10, 30 and 50 h) on the structure, pores morphology and microhardness of Ti/ZrO2 and Ti/Al2O3 compositions was studied. The X-ray diffraction analysis confirmed the composite formation for all milling times and sintering in the case of Ti/ZrO2 system. Decomposition of substrates during milling process of Ti/Al2O3 system was also observed. Additionally, the changes of lattice parameter as a function of milling time were studied. The morphology of powders and the microstructure of the sintered samples were observed by scanning electron microscopy (SEM). Also, analysis of microhardness and pores structure were performed.

The subject of the study was the production and characterization of three ceramic-metal graded composites, which differed in addition of the metallic phase. The following composites systems were investigated: Al2O3-Mo, Al2O3-Cu, Al2O3-W. Composites were produced by centrifugal slip casting method. This technique combines the classic casting of the slurry into porous molds with the action of centrifugal force. As a result, sleeve-shaped shapes with a metallic phase gradient were obtained. X-ray phase analysis have not revealed new phases in the produced composites. The type of metallic phase and its distribution in the ceramic matrix influenced the hardness of the produced composites.

In this paper, explain the preparation of CaTiO3 ceramics synthesized by the solid-state reaction method. Calcium carbonate and titanium dioxide were high energy mixed in stoichiometric amounts, and the obtained mixture was calcined at different temperatures (800, 900, 1000 and 1300ºC) for 2 h. The obtained samples were characterized by measurement of particle size, Energy Dispersive X-Ray (EDX) Analysis; differential thermal analysis, X-ray diffraction and SEM images. XRD patterns indicated that CaTiO3 ceramics with the structure of perovskite is obtained from calcined powders at 1,300°C for 2 h. SEM images show the formation of a very fine and homogeneous morphology. The measured values of electrical resistivity were within the typical range of insulating materials and approach values corresponding to insulating ceramics.

The aim of this research was to fabricate and study the properties of Bi1-x DyxFeO3 (for x = 0, 0.05, 0.07, 0.1) ceramics materials. Simple oxide powders Bi2O3, Dy2O3 and Fe2O3 were used to fabricate Bi1-xDyxFeO3 ceramics by mixed oxide method followed by free sintering. The study presents changes in microstructure and crystal structure as well as in dielectric properties and magnetic properties caused by modification of BiFeO3 with dysprosium dopant.

Ceramic injection moulding and gas pressure infiltration were employed for the manufacturing of alumina/AlSi10Mg composites. Porous ceramic preforms were prepared by mixing alumina powder with a multi-binder system and injection moulding of the powder polymer slurry. Then, the organic part was removed through a combination of solvent and thermal debinding, and the materials were finally sintered at different temperatures. The ceramic preforms manufactured in this way were infiltrated by an AlSi10Mg alloy. The microstructure and properties of the manufactured materials were examined using scanning electron microscopy, mercury porosimetry and bending strength testing. The results of transmission electron microscopy and scanning electron microscopy observations show that the fabricated composite materials are characterised by the percolation type of the microstructure and a lack of unfilled pores with good cohesion at the metal-ceramic interfaces. This is surprising considering that over 30% of the pores are smaller than 1 μm. The results show that the bending strength of the obtained composites decreased with increasing sintering temperature of the porous preforms.

This study attempted to manufacture an Y2O3 ceramic coating layer on a ceramic (AlN) substrate using aerosol deposition (AD) and investigated its macroscopic properties. Pure Y2O3 powder with a polygonal shape and average size of 5.0 μm was used as initial feedstock. Using aerosol deposition with suitable process conditions, an Y2O3 coating layer was successfully fabricated on aluminum nitride (AIN). The thickness of the manufactured coating layer was approximately 10 mm. The coating layer consisted of Y2O3 phase identical to that in the initial powder, and no additional oxides were identified. In regard to the roughness of the Y2O3 coating layer, the average roughness (Ra) measured 1.32 μm, indicating that the surface roughness was relatively even compared to the initial powder size (5 μm). Mechanical properties of the Y2O3 coating layer were measured using nano indentation equipment, and the indentation modulus of the Y2O3 coating layer fabricated by aerosol deposition measured 136.5 GPa. The interface of the coating layer was observed using TEM, and the deposition mechanism of the Y2O3 coating layer manufactured by aerosol deposition was also discussed.

Y2O3-MgO nanocomposites are one of the most promising materials for hypersonic infrared windows and domes due to their excellent optical transmittance and mechanical properties. In this study, influence of the calcination temperature of Y2O3-MgO nanopowders on the microstructure, IR transmittance, and hardness of Y2O3-MgO nanocomposites was investigated. It was found that the calcination temperature is related to the presence of residual intergranular pores and grain size after spark plasma sintering. The nanopowders calcined at 1000°C exhibits the highest infrared transmittance (82.3% at 5.3 μm) and hardness (9.99 GPa). These findings indicated that initial particle size and distribution of the nanopowders are important factors determining the optical and mechanical performances of Y2O3-MgO nanocomposites.

Thin films of crystallized LaCoO3 were grown on Si substrate by Pulsed Laser Deposition at different temperatures (750°C, 850°C and 1000°C). The structural characterization of the LaCoO3 thin films was done by combining several techniques: Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM), Transmission Electron Microscopy (TEM) and Grazing Incidence X-Ray Diffraction (GIXRD). The thin films crystallized in the expected rhombohedral phase whatever the deposition temperature, with an increase of crystallite size from 70 nm at 750°C to 100 nm at 1000°C, and an average thickness of the thin films of less than 200 nm. At 850°C and 1000°C, the thin films are crack-free, and with a lower number of droplets than the film deposited at 750°C. The grains of LaCoO3 film deposited at 850°C are columnar, with a triangular termination. At 1000°C, an intermediate layer of La2Si2O7 was observed, indicating diffusion of Si into the deposited film.

In this work, we present an extensive investigation of the effect of Al2O3 decoration on the morphological, structural and opto-electronic properties of a porous Si (Sip)/Cr2O3 composite. The Sip layers were prepared by the anodization method. Al2O3 and Cr2O3 thin films were deposited by physical vapour deposition. The morphological and micro-structural properties of Sip/Cr2O3/Al2O3 were studied using the scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction techniques. It was found that Al2O3 decoration with different concentration strongly affects the Sip/Cr2O3 microstructure mainly at the level of porosity. Variable angle spectroscopic ellipsometry demonstrates a strong correlation between optical constants (n and k) of Sip/Cr2O3/Al2O3 and microstructure properties. Dielectric properties of Sip/Cr2O3/Al2O3 such as electrical conductivity and conduction mechanism were explored using impedance spectroscopy over the temperature interval ranging from 340 to 410°C. A semiconductor to the metallic transition has been observed at high frequency.

A SrTiO3 electroceramic with perovskite structure was produced by the calcination of a mixture of SrCO3 and TiO2 intensively grounded by high energy milling. For this purpose, raw materials were mixed in stoichiometric amounts in a planetary type mill; the obtained powder mixture was calcined for 2 h at temperatures between 800 and 1300°C. Samples resulting from the calcination were characterized by XRD, FTIR, SEM analysis and electrical measurements. From XRD, it was determined that the SrTiO3 formed presents the cubic structure of perovskite. The complete reaction for SrTiO3 compound formation occurs at 1200°C. Micrograph observations indicate the presence of a homogeneous microstructure with tiny grain size. The measured values of electrical resistivity were within the typical range of insulating materials.

Surface phenomena play a major role in metallurgical processes; their operation results, among others, from the surface tension of liquid oxidic systems. One of the methods of determining surface tension of oxidic systems is performing calculations with Butler’s method. Surface tension was calculated for two- and three-component liquid oxidic systems typical of metallurgical processes. The determined dependence of surface tension in FeO-SiO2 at temp. 1773 K and CaO-SiO2 at temp.1873 K showed that with the growing participation of SiO2 surface tension decreased. Analogous calculations were performed for three-component systems: CaO-Al2O3-SiO2 and MnO-Al2O3- SiO2. The results of calculations of surface tension were determined for temp. 1873 K and compared with the results obtained by T. Tanaka et al. [19]. In both cases the increase of Al2O3 content resulted in a growth of surface tension. The simulation results were higher than experimental result, as compared to the literature data.