V 2016

Factors affecting the quality of ceramic colour layers, laser fused on glass substrate
This paper presents the results of a research conducted within the framework of the project titled “Innovative technology of colour, laser decoration of flat glass with ceramic agents”. The tests were performed with two permanent operating lasers: fibre laser SP-100 C with the capacity of 100 W and the wavelength of 1070 nm and the fibre laser GLPM with the capacity of 10 W and the wavelength of 532 nm. Hardened glass panes were used as a substrate. The materials tested in the study were ceramic colours based on lead and lead-free fluxes. The tests demonstrated that the laser parameters (power density, layout of the test setup) influence the quality of the coloured surface. The method applied for the test was determining the roughness parameters Ra and Rz and their dependence on the chemical composition of the tested colours. The influence of the filling type (dots, cross-form, linear) on the surface quality and colour intensity has been examined. The tests proved the dependence of the thickness of the decorative layer on the laser irradiation dose, as well the dependence of the Ra roughness parameter on the configuration of the laser exposition (irradiation on the coloured layer directly and through glass). The pictures enclosed are examples of decorations done with the use of the discussed methods.
Danuta Chmielewska Ph.D. Eng.

Formation the gradient composite from the ceramic-metal system by centrifugal slip casting
Demands for new composite materials are continuously increasing, as well as quality requirements for the new composites and methods of their preparation. Currently, directions of development in the production of composite materials focus on improving the properties and inventing of new methods to produce graded composites. The main problem for the engineers designing functionally gradient composites, is to control distribution of the particles along the gradient direction. One of the method to obtain FGM ceramicmetal composite is the centrifugal slip casting. This method combines the classical slip casting with the centrifugal force. It allows the production of finished products in the shape of a hollow cylinder. This investigation was carried out for the Al2O3-Ni system. The resulting composites are characterized by microstructure with the gradient concentration of nickel particles, which has a three-zone microstructure.
Justyna Zygmuntowicz M.Sc. Eng.

Fabrication and properties of Y3Al5O12 nanopowders obtained by microwave induced solution combustion synthesis
The paper presents results of combustion method utilization for yttrium aluminum garnet (YAG) ceramic powder fabrication. The combustion method is based on the high energy reaction between the metal nitrates and reducing agent. In this study, glycine and urea were used as the reducing substances. On the basis of the thermodynamic data, the temperature of the flame generated during the exothermic reaction was estimated, at above 1000°C. In this conditions YAG grains should crystallize. Combustion synthesis was performed using urea and glycine in stoichiometric quantities. After synthesis the reaction products were analyzed. Reaction with glycine lead to an amorphous product which was transformed to YAG phase after annealing at temperature of 1000°C. The obtained ceramic powder occurs in the form of agglomerates of particles having a diameter approx. 50 nm. In contrast, use of urea gives a powder which main phase is the YAG. The obtained ceramic powder is characterized by particles having a diameter of approx. 100 nm present in the form of agglomerates with internal porosity.
Magdalena Gizowska Ph.D. Eng.

Fabrication of CaF2 transparent ceramics using Hot Isostatic Pressing-HIP
Synthetic pearlescent pigments imitate the effects of brightness and iridescence that is the result of biomineralization in the animal world, exemplified by pearls, shells, fish scales, and wings of insects. These pigment, with diamond and pearl gloss, have high coating capacity, colour stability and resistance to UV light and weathering. Pigments are non-toxic, and their production meets environmental requirements. They are used for plastics decoration, preparation of pearlescent preparations, iridescent or giving high gloss metallic effect, as printing inks, cosmetics, automotive paints and ceramic paints. The most common pigments are pearlescent pigments on mica substrate with a low refraction index, having at least three layers of two materials with different refractive indices: TiO2, SnO2, Fe2O3. Interference layers are applied to the mica substrate in wet chemical process as a result of hydrolysis of appropriate salts of metals from transition groups. In calcination process, as result of thermal changes of hydroxyl compounds, the interference layers are permanently deposited on mica platelets in form of chromophoric metals oxides. Thermal resistance through appropriately selected parameters of the technological process is the criterion of applicability the synthetic pearl pigments in ceramics.
prof. ICiMB Cecylia Dziubak Ph.D. Eng.