International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Heat-resistant composites with a layered niobium-based matrix reinforced with single-crystal sapphire fibers have been obtained. The fibers were grown from the melt by the modified Stepanov method. The composites were prepared by solid-phase technology by diffusion welding of multilayer packages of foils of the Nb–0.1% C and aluminum alloy, interlaid with sapphire fibers in layers of a suspension mixture of Nb powder. The production of fibers, their structure and strength testing procedure are described. The formation of multilayer packets, the structure and results of bending strength tests of composites are presented

In contrast to the melting technologies for the production of high-temperature alloys in the solid-phase technology developed by us, a multi-layer structure of the future composite material is already set at the initial stage of the billet formation. In the work presented, the billets were assembled from Nb- and Mo-foils with one or two-sided coatings of carbon or Si-B. Layered structures of composites were formed during the diffusion welding of packets at 1500°C and a pressure of ~14 MPa. In the place of the coatings, layers of hightemperature carbides or intermetallic Si and B compounds with Nb and Mo formed, which occupied up to ~40% of the cross-sectional area of the composites. The strength and crack resistance at room temperature, strength at a temperature of up to 1500 °C, as well as the modulus of elasticity and density were measured. The presence of intermetallides in the structure of composites leads to a decrease in their density and an increase in the modulus of elasticity.