Non-isothermal synthesis of materials based on the MAX phases in the Ti-Si-C and Nb-Al-C systems

Abstract

The experimental results of self-propagating high-temperature synthesis of materials in Ti - Si - C and Nb - Al - C systems are presented. Mixtures of powders of Ti, Si, Nb, Al, and C were used as charge. The combustion thermograms of the Ti-Si-C system are investigated. It is shown that changes in the technological conditions of synthesis can substantially change the phase composition and microstructure of the final products. The optimal synthesis conditions were established, which made it possible to obtain a product with a maximum content of the target phases Ti3SiC2, Nb2AlC, Nb4AlC3. Under all conditions studied, the SHS method fails to obtain 100% of the MAX phase of stoichiometric composition. To obtain 100% stoichiometric MAX phases, additional heat treatment of the ground SHS products is necessary. The products obtained by high-temperature synthesis were characterized by X-ray, optical and scanning electron microstructural analysis methods.