The article presents the role of the ceramic layered moulds used in the investment casting method with new (certified) and recycled material from ceramic moulds (CM) after casting process. The materials that were obtained are mainly aluminosilicates and SiO2. The investigation of changes in the quality of ceramic moulds (including the recycled ceramic material) includes the chemical composition of the ceramics as recovered ceramic material, changes in the particle size of the layered covering material, the gas permeability during the pouring of liquid metal, and the creation of the porosity are presented. Than the thermophysical parameters and dimensional accuracy of the casting manufactured in the new ceramic layered shell moulds were analysed. Additionally the global cost savings and improved ecological conditions in the foundry and its surroundings was estimated.

In this work synthesis, sintering processes and properties of three groups of perovskite-type ceramics utilized in chosen electronic applications are briefly described. The first group includes high permittivity dielectrics based on relaxor ferroelectrics and new leadfree ceramics, destined for bulk and thick film capacitors. The second group comprises ceramics for low and high temperature thermistors and the third one nonstoichiometric conducting compounds containing doped SrMnO3 and SrCoO3, tested as electrode materials for solid state cells.

The paper reports the consequences of lanthanum modifications of barium bismuth niobiate (BaBi2Nb2O9) ceramics. The discussed materials were prepared by solid state synthesis and a one-step sintering process. The investigations are focused on dielectric aspects of the modification. The presented results reveal that the trivalent lanthanum ions incorporate twovalent barium ions, which is connected with the creation of A-site cationic vacancies as well as oxygen vacancies. Such a scenario results in significant decreasing in grain boundaries resistivity. The activation energy of grain boundaries conductivity is significantly reduced in the case of lanthanum admixture.

In this study, an artificial neural network application was performed to tell if 18 plates of the same material in different shapes and sizes were cracked or not. The cracks in the cracked plates were of different depth and sizes and were non-identical deformations. This ANN model was developed to detect whether the plates under test are cracked or not, when four plates have been selected randomly from among a total of 18 ones. The ANN model used in the study is a model uniquely tailored for this study, but it can be applied to all systems by changing the weight values and without changing the architecture of the model. The developed model was tested using experimental data conducted with 18 plates and the results obtained mainly correspond to this particular case. But the algorithm can be easily generalized for an arbitrary number of items.

The results of investigations of the rheological properties of typical ceramic slurries used in the investment casting technology – the lost

wax technology are presented in the paper. Flow curves in the wide range of shear velocity were made. Moreover, viscosity of ceramic

slurries depending on shearing stresses was specified. Tests were performed under conditions of three different temperatures 25, 30 and

35oC, which are typical and important in the viewpoint of making ceramic slurries in the investment casting technology.

In the light of the performed investigations can be said that the belonging in group of Newtonian or Non – Newtonian fluid is dependent

on content of solid phase (addition of aluminum oxide) in the whole composition of liquid ceramic slurries.

Extremely intense development of civilization requires from foundry casting technologies very high quality and not expensive castings. In

the foundries, there are many treatments that allow increasing of the final properties of produced castings such as refining, modification,

heat treatment, etc. One of the methods of increasing the quality of the casting by removing inclusions from the liquid alloy is filtration.

The use of ceramic-carbon foam filters in filtration process is still analysed phenomenon that allows improving the final properties of

castings. A modern method of research, testing and synthesis of innovative chemical compositions allows improving the properties of such

filters. In the paper the evaluation of application properties of developed ceramic-carbon bonded foam filters is presented. The quality of

the foam filters is evaluated by Computer Tomography and foundry trials in pouring of liquid metal in test molds. Additionally computer

simulations were made to visualize the flow characteristics in the foam filter. The analysed filters are the result of the research work of

Foundry Research Institute and the Institute of Ceramics and Building Materials, Refractory Materials Department in Gliwice.

While analyzing shape accuracy of ferroalloy precision castings in terms of ceramic moulds physical anisotropy, low-alloy steel castings

("cover") and cast iron ("plate") were included. The basic parameters in addition to the product linear shape accuracy are flatness

deviations, especially due to the expanded flat surface which is cast plate. For mentioned castings surface micro-geometry analysis was

also carried, favoring surface load capacity tp50 for Rmax = 50%.

Surface load capacity tp50 obtained for the cast cover was compared with machined product, and casting plate surface was compared with

wear part of the conveyor belt. The results were referred to anisotropy of ceramic moulds physical properties, which was evaluated by

studying ceramic moulds samples in computer tomography equipment Metrotom 800.

The rocks quarried in the neighboring Rutki and Ligota Tułowicka deposits (vicinity of Niemodlin) represent a single petrographic variety of basalt, i.e. nephelinite. The presence of nepheline (the mineral belonging to the group of feldspathoids) that forms the light-colored component of the groundmass is the characteristic feature of these rocks. Nepheline is accompanied by fine crystals of pyroxene and, occasionally, magnetite. Distinctly larger pyroxene and olivine phenocrysts are dispersed within the groundmass. Neither minerals of the groundmass nor the phenocrysts of the pyroxenes reveal any signs of chemical weathering. However, such alterations are clearly visible in the phenocrysts of olivine. The basalt raw materials of both deposits are utilized mainly for the production of various assortments of crushed road aggregates and as components of concretes. These applications require the aggregates with the grain sizes >2 mm. There is also a possibility to utilize coarse-grained basalt aggregates for the manufacturing of rock wool. This is due to a favorable property of the rocks from Rutki and Ligota Tułowicka that is their relatively low content of magnetite resulting in the low capability of the molten basalt to crystallize. The chemical weathering of the olivine phenocrysts have proceeded toward the formation of clay minerals, among which those of the smectite group prevail. Their elevated quantities occur in the finest aggregate assortment, i.e. 0–0.85 mm. The fineness of this grain fraction and its elevated quantity of clay minerals are two favorable features to utilize this part of the basalt aggregate by the heavy clay industry as an additive improving the physico-mechanical parameters and providing the required red color of ceramic products..

In this paper the current status of microplasma devices and systems made in the LTCC technology is presented. The microplasma characteristics and applications are described.We discuss the properties of the LTCC materials, that are necessary for reliable operation of the sources. This material is well known for its good reliability and durability in harsh conditions. Still, only a few examples of such microplasma sources are described. Some of them have been developed by the authors and successfully used for chemical analysis and synthesis.

La0,7Ca0,3MnO3 polycrystalline were synthesized from La2O3, CaO and MnO2 powder mixture using a solid state reaction technique. The compound powders were obtained through the free sintering method at different temperatures and sintering times in order to study the influence of technological conditions on Ca doped La manganites. The most important physical features as structure, microstructure and morphology were described after X-ray diffraction investigation. Photographs of the specimen fractures were taken with SEM (scanning electron microscope) and they revealed high porosity of the tested material and great tendency for its grains to create agglomerates. Influence of doping and technological conditions on lattice parameters were studied by means of Rietvield analysis. The XRD measurements reveal that La0,7Ca0,3MnO3 has orthorhombic symmetry with Pnma space group.

This paper describes preparation methodology and research results of newly developed materials from post-production fibrous waste that are resistant to high temperatures. Widely available raw materials were used for this purpose. Such approach has significant impact on the technological feasibility and preparation costs. Obtained materials were verified via applying of various tests including characterization of shrinkage, porosity, density and water absorption as well as X-ray analysis (XRD), followed by mechanical bending and compressive strength determination.

Based on the research results, the possible applications of materials as thermal insulators were indicated.

In this study, it was achieved by using the method of impulse noise to detect internal or surface cracks that can occur in the production of ceramic plates. Ceramic materials are often used in the industry, especially as kitchenware and in areas such as the construction sector. Many different methods are used in the quality assurance processes of ceramic materials. In this study, the impact noise method was examined. This method is a test technique that was not used in applications. The method is presented as an examination technique based on whether there is a deformation on the material according to the sound coming from it as a result of a plastic bit hammer impact on the ceramic material. The application of the study was performed on plates made of ceramic materials. Here, it was made with the same type of model plates manufactured from the same material. The noise that would occur as a result of the impact applied on a point determined on the materials to be tested has been examined by the method of time-frequency analysis. The method applied gives pretty good results for distinguishing ceramic plates in good condition from those which are cracked.

This paper presents an experimental study on chicken egg white solution ultrafiltration, where membrane fouling has been the main point of concern. Separation process has been performed with a 150 kDa tubular ceramic TiO2/Al2O3 membrane. The operating parameters have been set as follows: transmembrane pressure 105–310 kPa, cross-flow velocity 2.73–4.55 m/s, pH 5 and constant temperature of 293 K. Resistance-in-series model has been used to calculate total resistance and its components. The experimental data have been described with four pore blocking models (complete blocking, intermediate blocking, standard blocking and cake filtration). The results obtained show that the dominant fouling mechanism is represented by cake filtration model.

Preliminary tests aimed at obtaining a cellular SiC/iron alloy composite with a spatial structure of mutually intersecting skeletons, using a

porous ceramic preform have been conducted. The possibility of obtaining such a composite joint using a SiC material with an oxynitride

bonding and grey cast iron with flake graphite has been confirmed. Porous ceramic preforms were made by pouring the gelling ceramic

suspension over a foamed polymer base which was next fired. The obtained samples of materials were subjected to macroscopic and

microscopic observations as well as investigations into the chemical composition in microareas. It was found that the minimum width of a

channel in the preform, which in the case of pressureless infiltration enables molten cast iron penetration, ranges from 0.10 to 0.17 mm. It

was also found that the ceramic material applied was characterized by good metal wettability. The ceramics/metal contact area always has

a transition zone (when the channel width is big enough), where mixing of the components of both composite elements takes place.

The work presents the results of the studies of Co-Cr-Mo casting alloys used in the production of frame casts of removable dentures,

crowns and bridges in dental prosthetics. The studies were performed on four Co-Cr-Mo alloys of different contents of Mo, W and other

additives. Electrochemical tests were performed, which aimed at examining the corrosion resistance of the alloys and observing the alloy

structure after chronoamperometric tests with the potential in the area of the occurrence of the passive layer breakpoint. The alloy

microstructure images after chronoamperometric tests show the presence of non-uniformly distributed general corrosion. Moreover, a

project of cobalt alloy casting was elaborated using a ceramic mold casting. Additionally, analysis of the obtained microstructure was

performed. The microstructure of the examined alloys was of the dendrite type. This microstructure was chemically inhomogeneous and

consisted of an austenitic matrix formed by a solid cobalt solution and chromium in the core dendritic structure.

Nickel alloys belong to the group of most resistant materials when used under the extreme operating conditions, including chemically

aggressive environment, high temperature, and high loads applied over a long period of time. Although in the global technology market

one can find several standard cast nickel alloys, the vast majority of components operating in machines and equipment are made from

alloys processed by the costly metalworking operations. Analysis of the available literature and own studies have shown that the use of

casting technology in the manufacture of components from nickel alloys poses a lot of difficulty. This is due to the adverse technological

properties of these alloys, like poor fluidity, high casting shrinkage, and above all, high reactivity of liquid metal with the atmospheric air

over the bath and with the ceramic material of both the crucible and foundry mold. The scale of these problems increases with the expected

growth of performance properties which these alloys should offer to the user.

This article presents the results of studies of physico-chemical interactions that occur between theH282alloy melt and selected refractory

ceramic materials commonly used in foundry. Own methodology for conducting micro-melts on a laboratory scale was elaborated and

discussed. The results obtained have revealed that the alumina-based ceramics exhibits greater reactivity in contact with the H282 alloy

melt than the materials based on zirconium compounds. In the conducted experiments, the ceramic materials based on zirconium silicate

have proved to be a much better choice than the zirconia-silica mixture. Regardless of the type of the ceramic materials used, the time and

temperature of their contact with the nickel alloy melt should always be limited to an absolutely necessary minimum required by the

technological regime.