The aim of the study was to evaluate the applicability and performance of polyglycerol- and sucrose-based polyols as components of a simplified formulation of polyurethane adhesives. Colloidal silica was used as a viscosity control and reinforcing agent. The adhesives were examined in terms of reactivity, thermal stability, viscosity, work of adhesion, wetting, surface energy, and bonding strength on wooden substrates. Silica was found to increase gelling time, but markedly improved bonding strength and adhesion with substrates. Bonded solid beech wood samples prepared at 80, 110, and 130 °C showed shear strengths between 7.1 MPa and 9.9 MPa with 100% wood failure. The renewable resource-based polyols were demonstrated to be useful in formulation of polyurethane adhesives for furniture industry—especially with silica as a filler.

Digital light processing (DLP) belongs to additive manufacturing techniques and is frequently used in shaping ceramics. The paper concerns the adjustment of the DLP method to metal-reinforced ceramics, especially dispersions containing high concentrations of Al₂O₃ (45 vol%) and molybdenum or nickel particles (0.5 vol%). Different glycol acrylates, deflocculants (polyelectrolytes and diammonium hydrogen citrate), and photoinitiators (Omnirad group) were examined regarding their influence on the rheological properties of the dispersions and the cure depth under the external halide UV lamp and LED projector built into the 3D printer. In the examined systems, the cationic polyelectrolyte KD1 dissolved in 2-butanone allowed to obtain dispersions of the lowest viscosity. Printing parameters (light exposure time, single layer height) were matched, and the properties of the materials were examined. The Vickers hardness of the sintered bodies equalled 19.4 GPa, 14.5 GPa and 17.3 GPa for Al₂O₃, Al₂O₃-Ni and Al₂O₃-Mo samples, respectively. The microstructure was analyzed using SEM, followed by EDS and XRD. The addition of only 0.5 vol% of Ni has improved the fracture toughness of alumina by up to 36–40% (according to Niihara and Anstis equations). The exemplary objects in the form of cog wheels were printed and densified at 1550 °C in a reductive atmosphere of Ar/H₂.

This study’s main goal was to obtain and characterize Al₂O₃-Cu-Ni composites with different metallic phase content. The study analyzed the three series of samples differing in the metallic phase 5, 10, 15 vol.% volume contents. An identical volume share of the metallic components in the metallic phase was used. Ceramic–metal composites were formed using uniaxial pressing and sintered at a temperature of 1400 °C. The microstructural investigation of the Al₂O₃-Cu-Ni composite and its properties involved scanning electron microscopes observations and X-ray diffraction. The size of the metallic phase in the ceramic matrix was performed using a stereological analysis. Microhardness analysis with fracture toughness measures was applied to estimate the mechanical properties of the prepared materials. Additionally, magnetic measurements were carried out, and the saturation magnetization was determined on the obtained magnetic hysteresis loops. The prepared samples, regardless of the content of the metallic phase in each series, were characterized by a density exceeding 95% of the theoretical density. The magnetic measurements exhibited that the fabricated composites had ferromagnetic properties due to nickel and nickel-rich phases. The hardness of the samples containing 5, 10, 15 vol.% metallic phases decreased with an increase in the metallic phase content, equal to 17.60 ± 0.96 GPa, 15.40 ± 0.81 GPa, 12.6 ± 0.36 GPa, respectively.