Processing of V2AlC MAX phase: Optimization of sintering temperature and composition

Abstract

The Vanadium MAX phase (V2AlC) was synthesized by the pressureless sintering method using elemental V, Al, and C powders as starting materials. The synthesis process involves varying the aluminum molar ratios and temperature to fully realize the optimal conditions for MAX phase synthesis. Systematic variation of the aluminum molar ratio in the range of 1.2 to 1.4 reveals that an aluminum ratio of 1.2 minimizes side reactions and compensates for aluminum loss due to the compound's volatility, optimizing Vanadium MAX phase synthesis. Furthermore, this research examines the profound impact of synthesis temperature on the composition and structure of the Vanadium MAX phases. The results indicate that the ideal temperature for achieving maximum yield, phase purity, crystallinity, and the desired microstructure is 1300 °C. Scanning electron microscopy (SEM) analysis reveals the intricate nanolaminate structure of MAX phases, characterized by fluctuations in layer thickness. Notably, we observe an average particle size of 8.27 μm, with sample 1 and sample 3 exhibiting the largest and smallest sizes at 9.51 μm and 7.28 μm, respectively. The highest conductivity, reaching 7.19E-5 S/m, and the purest samples are consistently obtained at 1300 °C with an aluminum ratio of 1.2, reaffirming the optimized conditions. In summary, this research unveils the intricate chemistry of factors influencing the synthesis of Vanadium MAX phases, shedding light on their immense potential and offering new perspectives and possibilities in MAX phase synthesis.