Advanced ceramic materials
The main activity of the research group is to investigate advanced methods of preparing multifunctional homogeneous and heterogeneous ceramic materials (biomaterials, electromaterials and structural materials), to characterize their structure on various dimensional scales, to quantify structure-property-function relationships on the various structural levels and to develop procedures for engineering the properties of this class of materials in the process of their preparation.
Expertise, processing and characterization
- Particles and fibres synthesis
We use and innovate traditional as well as non-conventional techniques for synthesizing of ceramic oxide particles. The research is aimed on synthesis of particles with controlled morphology and composition especially by wet chemical techniques (sol-gel, precipitation, polymeric method…) using microwave, ultrasound and other high-energy fields. We utilize electrospinning and dip-coating methods for fabrication of ceramic and polymer/ceramic composite fibres with controlled size, shape and arrangement.
In Advanced Ceramic Materials group, we use different shaping technologies and smart processing that allow us to work with a wide range of materials. We have a lot of experience with various wet and also dry shaping techniques such as slip casting, gel casting, freeze casting and tape casting, electrophoretic deposition, injection moulding, extrusion and co-extrusion, press forming via die press, uniaxial and isostatic pressing.
- Ceramic 3D printing and CAD/CAM machining of ceramic parts
We are very well established in the field of 3D printing (additive manufacturing). It means that we are able to produce three dimensional objects of diverse complexity by stacking individual layers straight from CAD data. Our group is also able to produce ceramic complex parts using CAD/CAM machining of ceramic blanks – from the blanks fabrication, through CAD/CAM design and machining to final sintered product. We use 5 axes CNC milling machine equipped with diamond tools, capable high speed machining operations. These technologies allow the production of high-performance ceramic parts mainly for testing part’s design and functionality or fabrication of prototypes, single parts and small-scale series.
The high temperature diffusion process called sintering is the key step in the production of all advanced ceramic materials. The driving force of this step is lowering of the surface energy. In the case of special and/or high performance materials, it is very difficult to optimise whole process. The final mechanical, functional or physical properties can be deteriorated by high residual porosity content, enormous grain size or other unwanted phenomena. Thanks to our know-how and experience, we are capable to provide extensive analyses of sintering behaviour (via dilatometry measuring, numeric modelling and calculations) and prevent such negative effects and optimise sintering procedure to achieve demanded quality of the final product.
- Particle, powder and ceramic analysis and characterisation
Basic characteristics of the particles, powders and ceramic bodies in green or sintered state (particle and grain size and shape, surface area, porosity, phase and chemical composition, thermal behaviour) are analysed by means of laser diffraction, scanning electron microscopy, BET method (using nitrogen adsorption), X-ray diffraction, energy dispersive spectroscopy and thermogravimetry coupled mass spectroscopy.
Catalytic performance of ceramic particles and powders can be characterized using reactors in a liquid and gaseous reactant medium with a reaction product analysis using mass spectrometry.
We can determine micro-rheology using dynamic light scattering, zeta potential and electrophoretic mobility using electrophoretic light scattering, and molecular weight using static light scattering. Rheological characterisation includes polymers, liquids, adhesives and other samples using a wide range of shear and extensional conditions.
Laboratories are equipped with devices for synthesis, shaping and sintering of advanced ceramic materials and for characterization of their properties.
- Ceramic particle and fibre synthesis
Microwave hydro/solvo-thermal reactor (up to 300 °C, 200 bar), ultrasonic probe/reactors, lab spray dryer, electrospinning machine.
- Shaping and preparation of ceramics
Ceramic injection moulding machine, double-screw ceramic extrusion machine with granulator, electrophoretic deposition gauge, tape-casting machine, uniaxial ceramic press, cold isostatic press, CVD system (up to 1600 °C), 3D printing machine, drying climatic chamber, 5-axes CNC milling machine (for milling of ceramics).
- Low and high temperature processes
Low temperature furnaces (up to 1200 °C) and furnaces for thermal and catalytic debinding, high temperature superkanthal furnaces (sintering up to 1800 °C in air atmosphere), high temperature furnace (sintering up to 2300 °C in vacuum, hydrogen, resp. inert atmosphere), hot press Spark plasma sintering (sintering up to 2400 °C with possibility of uniaxial pressure 80 MPa and heating rates up to 1000 °C/min), high-temperature furnace with rapid heating rate, two high temperature dilatometers working in temp. range from -150 to 1750 °C in air or up to temperature of 2000 °C in inert atmosphere.
- Analytical and other equipment
Particle size, specific surface-area and pore-size analysers, thermogravimetrical (TGA-DTA/DSC) analysers with possibility of TGA on samples with large volume – up to 17 ml (sample of 50 mm in height and 20 mm in diameter), liquid chromatograph, mass spectrometer, equipment for rheological and electrokinetic measurements, systems for testing thermal and (photo)catalytic properties of ceramics, equipment for characterization of piezoelectric materials, complete ceramographic laboratory, very precise analytical scales and other.
» Kulicke and Soffa (IL) – Sintering analyses of ceramic materials via high-temperature dilatometry.
» BOSCH (CZ) – Measuring of thermal expansion of ceramic composite plates.
» Energovýzkum (CZ) – Research on the technological and material properties of powdered materials.
» Somet Teplice (CZ) – Sintering analyses of new construction materials.
» Škoda JS (CZ) – Study of mechanical properties of containment material for the storage of nuclear waste.
» Lithoz (AT) – Thermogravimetrical analyses and high-temperature dilatometry of Al2O3 samples.
» ZrO2 (CZ) – Development of ceramic semiproducts for milling of ceramic dental structures.
» CoorsTek Turnov (CZ) - Characterization of ceramics for ballistic armours.
» EMPA (CH) – Research on ceramic core-shell composite rods via thermoplastic co-extrusion.
» MUni Brno (CZ) – Research on the processing of highly flexible Al2O3 and ZrO2 electrodes for plasma discharge.
» Stockholm University (SE) – Sintering of transparent alumina ceramics via spark plasma sintering.
» Josef Stefan Institute (SI) – Co-operation on the processing of mesoporous ZrO2.
» University of Duisburg-Essen (DE) – Research on the nanoparticle processing technology.
» ICMATE-Genova (IT) – Hydrothermal syntheses of electroceramics.
» ASCZ-IPM (Academy of Science, CZ) – Research on mechanical properties of ceramic materials.