Self-propagating high temperature synthesis of layered composite Ti/Hf/Ta/Ni/ceramics materials

The formation of compounds of refractory metal foils (Ti, Hf, Ta, Ni) with ceramic layers formed as a result of combustion of reaction tapes rolled from powder mixtures (Ti + 0.65C, Ti + 1.7B and 5Ti + 3Si) was experimentally studied. The microstructure, elemental and phase compositions of multilayer composites obtained by self-propagating high-temperature synthesis were studied using scanning electron microscopy and X-ray diffraction analysis. The influence of synthesis conditions (initial temperature, applied pressure) and the initial structure of the samples on the speed of propagation of the combustion wave front, microstructure, phase composition and strength characteristics of the resulting layered materials was revealed. It has been shown that connections in the combustion mode between metal foils and reaction tapes rolled from powder mixtures are ensured due to reaction diffusion, mutual impregnation and chemical reactions occurring in the reaction tapes and on the surface of metal foils. The strength characteristics of the resulting materials (up to 275 MPa at 25$^{\circ}$C, up to 72 MPa at 1100$^{\circ}$C) were determined using a three-point loading scheme. The results are of interest for the development of structural materials operating under extreme conditions.