Synthesis of Al2OC whiskers by heat treating bulk Ti3AlC2 in a carbon-containing environment

• Al2OC whisker was fabricated for the first time.
• Growth of Al2OC whiskers obeys a vapor-liquid-solid process.
• Thermal stability of Ti3AlC2 in a carbon-containing atmosphere was investigated.

Al2OC whisker was fabricated for the first time by treating bulk Ti3AlC2 at 1250–1300 °C in a furnace with carbon heater. Al2OC whiskers grow along [0 0 0 1] direction. They have the dimensions of 50 nm to 2 μm in diameter and several hundred micrometers in length, which are tunable by adjusting the heat-treating conditions. The formation of Al2OC whiskers obeys a vapor-liquid-solid (VLS) process and results from the reaction between the evaporated Al from Ti3AlC2 and CO in the atmosphere. In addition, CO can accelerate the decomposition of Ti3AlC2. This result provides meaningful information for the application of Ti3AlC2 in CO-containing atmosphere at high temperatures.