Combustion synthesis of high yield Ti3SiC2 from TiC0.67 with induction heating assistance

Abstract

Combustion synthesis of Ti3SiC2 MAX phase was first reported more than 30 years ago, yet it has not become a widespread method, because of unavoidable presence of TiC as a by-product. Here we report high-purity Ti3SiC2 powders free of TiC by-products synthesized with a high yield using TiC0.67 and elemental powders as starting materials by combustion synthesis method with an induction heating (IH) assistance. By using IH assistance, ignition of the reaction and subsequent post-heating aimed to complete the reaction were done in one process. The addition of TiC0.67 was used to control the exothermic effect of the reaction and facilitate the reaction between three elements. Moreover, to improve the reactivity of the starting powders, a small amount of Al was added. As a result, TiC-free high-purity Ti3SiC2 powders were synthesized under IH ignition and post-heating at 1400 °C for 10 min in Ar flow. It was concluded that the combustion synthesis reaction can be effectively controlled using IH assistance, resulting in the product with a high yield. Furthermore, the addition of TiC0.67 provided a direct synthetic route of Ti3SiC2 without intermediate phases, and the addition of Al decreased the negative effects of oxygen in the starting powders. The present method bridges the advantages of the combustion synthesis method such as short time and low energy consumption and precise and fast control of heating conditions provided by IH, and is considered to be perspective for the synthesis of other MAX phases.