Synthesis of Ti ₃ SiC ₂ Powders: Reaction Mechanism

Abstract

Titanium silicon carbide (Ti 3 SiC 2 ) and Ti 3 SiC 2 ‐based composite powders were synthesized by isothermal treatment in an inert atmosphere as a function of initial compositions (mixtures). A high content of TiC was obtained in the final product when the initial mixtures contained free carbon. The use of TiC as a reagent was unsuccessful in obtaining Ti 3 SiC 2 . High Ti 3 SiC 2 conversion was found for the initial mixtures containing SiC as the main source for silicon and carbon. An initial mixture with a large excess of silicon, 3Ti/1.5SiC/0.5C, was needed to obtain high‐purity Ti 3 SiC 2 . A reaction mechanism, where Ti 3 SiC 2 nucleates on Ti 5 Si 3 C crystals and grows by long‐range diffusion of Ti and C, is proposed. The reaction mechanism was proposed to be based on silicon loss during the formation of Ti 3 SiC 2 .