Layered composite material of niobium–ceramic

Abstract

Layered composite materials based on niobium and cermet were produced via self-propagating high-temperature synthesis of pre-structured samples using metal foils (Ti, Nb, Ta, Ni) and reaction tapes (Ti + 1.7B) and (5Ti + 3Si). Reaction tapes for synthesis were produced by rolling process of powder mixtures. The microstructure, elemental and phase compositions of the synthesized multilayer composite materials were studied by scanning electron microscopy and X-ray phase analysis. Particular attention was paid to the formation of intermediate layers and surface modification occurring during combustion. The strength characteristics of synthesized materials were determined according to the three-point loading scheme at temperatures of 1100°C. The analysis of obtained materials showed that joining in the combustion mode of metal foils and reaction tapes is provided due to reaction diffusion, mutual impregnation and chemical reactions occurring in the reaction tapes and on the surface of metal foils. The formation of thin intermediate layers in the form of cermet and eutectic solutions provides the synthesized multilayer materials with good strength properties up to 87 MPa at 1100°C. These results are of interest for the development of structural materials operating under extreme conditions.