Synthesis of Ti2AlC in KBr Melt: Effect of Temperature and Component Ratio

Abstract

MAX phases of various compositions have recently gained increasing attention due to their layered structure and the combination of properties typical of both ceramic materials and metals. Consequently, the development of scalable methods for synthesizing these compounds with enhanced phase purity is of significant importance. In this work, the effects of different parameters on the composition and properties of the Ti₂AlC MAX phase were investigated, particularly when using a protective salt melt (KBr as an example). The study focused on the ratios of the starting reagents (n(Ti) : n(Al) : n(C)), the temperature, and the duration of heat treatment. It was found that at 1100°C, the highest yield of Ti₂AlC (94.4%) was obtained with a molar ratio of n(Ti) : n(Al) : n(C) = 2 : 1.1 : 0.9. The results showed that varying the synthesis temperature between 900 and 1100°C had a minimal impact on the target MAX phase content (ranging from 94 to 96%), with the maximum Ti₂AlC content observed at 1000°C. Additionally, the influence of synthesis temperature (900, 1100, and 1200°C) on the microstructure, thermal behavior in an air flow, and the electron work function was also studied.