Low infrared emissivity of a Ti3AlC2 MAX ceramic for high-temperature thermal camouflage

Abstract

Thermal camouflage technology can effectively hide an object by lowering its infrared emissivity and reducing its surface temperature. So far, it has been a challenge to realize thermal camouflage at high-temperatures with a single material. Here, we report a Ti3AlC2 MAX phase material that exhibits excellent thermal camouflage properties from room temperature to 500 °C, and maintains a low emissivity of 0.25 at 500 °C, which is difficult to achieve for most metals due to the rapid increase in emissivity caused by oxidation. The thermal camouflage mechanism of Ti3AlC2 was analyzed on the basis of experimental results and first-principles calculations, providing a feasible approach to select other MAX phases (such as Ti3SiC2, Cr2AlC, and Ti2AlC) with attractive thermal camouflage performance. Ti3AlC2 and other MAX phases are promising candidates for thermal camouflage applications due to their low emissivity, high-temperature stability, good oxidation resistance and ease of fabrication.