Abstract
The increasing interest in innovative ceramics with unique properties for medicine, dentistry or the space industry causes a constant search for new and better materials. Furthermore, new manufacturing techniques are developed, or the conventional methods are improved to meet the customer's expectations. The promising materials for mentioned applications are ceramic matrix composites, also known as CMC, reinforced e.g. with metallic particles. In accordance with the used metal type, products with new or improved properties can be obtained. The reinforcement of metallic particles in the ceramic matrix can increase, e.g. thermal and electric conductivity and fracture toughness. More and more emphasis is placed on obtaining components with complex shapes quickly and relatively cheaply. In the ceramics industry, the most significant potential is seen in 3D printing methods such as digital light processing (DLP) or direct-ink-writing (DIW). They are low-waste, have almost unlimited possibilities regarding the shape and size of the formed element, and can be used for unit and serial production. 3D printing methods allow for obtaining composite elements of complex shapes with strictly designed and controlled geometry. It should be emphasized that in several 3D shaping methods, the consolidation of ceramic suspensions occurs due to radical photopolymerization. Metal particles can catalyze this reaction and hinder the consolidation of formed dispersion because they absorb light in the UV wavelength range typically used in 3D printers. 
The aim of this research was the preparation of ceramic matrix composites reinforced with metallic phase from colloidal systems and metallic precursors. Nanosized Al2O3 and/or ZrO2 powders were used in this study. A fine-grained metallic phase was obtained by using a metallic precursor. Rheological, zeta potential and pH measurements of ceramic dispersions were carried out to determine their stability and the influence of individual components on the examined parameter. New, combined forming techniques were used, such as digital light processing (DLP), photochemically assisted direct-ink-writing (UV-DIW) and gelcasting. The conditions for the sintering of composite samples were selected, and this process was carried out, among others, in a reducing atmosphere (e.g. H2/Ar). For obtained sintered bodies, relative density, mechanical strength, hardness, fracture toughness, XRD analysis and microstructure observations were examined.

Acknowledgements:This work was financially supported by the Polish National Science Centre, project No 2018/30/Q/ST8/00205.
Research was funded by the Warsaw University of Technology within the Excellence Initiative: Research University (IDUB) programme.