Layered-Fibrous Composite with a Niobium-Based Matrix Reinforced with Single-Crystal Sapphire Fibers

In this paper, we obtain samples of composite materials with a layered niobium-based matrix unidirectionally reinforced with single-crystal sapphire fibers using the solid-phase method of diffusion welding. Sapphire fibers are obtained by the Stepanov method (EFG). As a result of tests, the dependences of the strength of such fibers on the length are obtained for the first time. The strength values ​​correspond to the global level. X-ray spectral microanalysis of the obtained materials is performed. The formation of solid solutions and intermetallic compounds of the Nb-Al system during composite-structure formation is established. Strength tests (500–700 MPa) are carried out and the effective surface energy of fracture of the composites is determined ((9–49) × 10 3 J/m 2 ), and their correlation with the fabrication modes is established. The features of the fracture structure of such materials and the processes inhibiting its fracturing under load are studied.