IV 2016

Preliminary study on pastes of selected ceramic biomaterials for use in 3D printing
The aim of this work was to prepare pastes for 3D printing made of selected biomaterials and to attempt an extrusion of pastes through the nozzle with an inside diameter of 0,45 mm. For the aim of the study powders of biomaterials were selected, their particle size was measured and powders morphology was observed. Pastes with different contents of plasticizing substances made of four types of biomaterials used in bone surgery: the calcite, aragonite, hydroxyapatite and tricalcium phosphate – ß-TCP were prepared. The method of pastes extrusion process with simultaneous measurement of the force needed to form the bands was determined using a special adapter for testing machine. Evaluation of the quality of the bands (microstructure uniformity, surface morphology of bands, capacity to form a junction between bands and the deformability) was performed by observations in the stereomicroscope and scanning electron microscope. Then the most suitable pastes recipes were selected. Technological details of their preparation have to be optimized for their application in selected printing device. The experience resulting from this work will be used in designing ceramic pastes systems for application in 3D printers.
Zdzisław Wiśniewski M.Sc.

Coloured glasses for small producers of art glass
The production technology of coloured glasses is known for a long time. The aforementioned glasses differ in chemical composition to such a degree, that we cannot combine them in any way, without having in mind their physical and chemical parameters. Manufacturers of coloured glasses, which are widely used commercially, do not provide compositions of the produced glasses. The project was to create an alternative and cheap coloured glasses, which allow any colour combinations, using waste material, in particular glass cullet from recycling.
Anna Kuśnierz Ph.D. Eng.

Influence of the impregnation process on the microstructure of refractory materials
The work presents the possibilities of achieving the favourable microstructural changes of refractory products resulting from the application of non-standard technological operation, during the impregantion proccess. Impregnation of aluminosilicate fi red materials with castable suspensions of alumina powder causes microstructural parameters changes, comprising of open porosity, the reduction of pore diameter distribution median and average pore diameter by 86,6% and 71,1%, respectively. The application of the impregnation process enables obtaining aluminosilicate materials with a 42% shore of pores having diameters less than 1 µm. The microstructural changes result should increase the resistance of corrosive and erosive materials to aggressive destructive factors. An area of application for the improved refractory materials have been suggested.
Tamara Pochwała M.Sc. Eng.

Fabrication of CaF2 transparent ceramics using Hot Isostatic Pressing-HIP
The paper presents the research on obtaining a transparent ceramics made from calcium fl uoride. The researchers used two types of calcium fluoride powders which were characterized by XRD (phase content), SEM (microstructure), grain size analysis and thermal analysis DTA-TG, with temperature up to 600oC in atmosphere of synthetic air, so as to defi ne a temperature of decomposition. The raw materials used were different in terms of grain size. Powder (under symbol C1) provided by Sigma-Aldrich has an average grain/agglomerate size Dv 50 at the level of 20,3 µm, whereas powder (under symbol C2) provided by ABCR has a wider range of grain/agglomerate size distribution and Dv 50 was 8,9 µm. A strong tendency to agglomeration was proved by SEM analysis. X-ray phase analysis indicated a cubic phase in case of both powders. Differences between materials were noticed during thermogravimetric analysis, where for powder provided by ABCR some contamination was observed, which was analyzed as residual carbon after synthesis. For the purpose of further research, cylindrical samples were obtained by die-pressing method from both powders and sintered in temperature range of 900–1350oC, in protective atmosphere of argon or vacuum. Additionally, the samples were densifi cated by hot isostatic pressing under pressure of 2000 bar of argon and temperature 1300oC. The results of thermal conductivity and fluoresces spectrum of raw calcium fl uoride and doped with ytterbium (2% at.) were shown in this paper. 
Krzysztof Perkowski Ph.D. Eng.