Self-Propagating High-Temperature Synthesis of Nb2AlC Max-Phase from Powder Mixture Nb + Al + C + Mg + Mg(ClO4)2

Abstract

The technological foundations for producing the MAX phase Nb₂AlC by the method of self-propagating high-temperature synthesis (SHS) from powdered mixtures of Nb + Al + C with an energy additive Mg + Mg(ClO₄)₂ have been developed. As a result of the synthesis, a multiphase powder is formed, containing the target phase Nb₂AlC and secondary phases NbC, Nb₂C, AlNb₂, MgO, and MgAl₂O₄. It has been shown that the phase composition of the product and the yield of the target phase are controlled by the carbon content in the charge. Reducing the carbon content in the charge relative to its stoichiometric ratio leads to a decrease in the niobium carbide content in the product. Optimal component ratios have been determined to obtain, after acid leaching, a powder containing ~82 wt % Nb₂AlC.