Abstract
This study investigated the effects of the SiO₂–NiCr composition and thermomechanical consolidation method on the microstructure, phase composition, mechanical properties, and tribological behavior of composites produced by spark plasma sintering (SPS) and hot pressing. The samples were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray fluorescence analysis, Vickers hardness measurements, and tribological testing. The composites exhibited a heterogeneous cermet structure, with Ni and Cr distributed in the metallic constituent and SiO₂ forming the oxide phase. The maximum Vickers hardness, 2020.2 ± 165.9 HV, was recorded for the hot-pressed sample with an SiO₂/NiCr ratio of 70/30. The minimum mean coefficient of friction (0.135) was obtained for the SPS-produced sample with a 50/50 composition. The results demonstrate that both composition and consolidation method substantially affect the microstructure, phase composition, hardness, and tribological properties of SiO₂–NiCr composites.