|About this Abstract
||3rd World Congress on High Entropy Alloys (HEA 2023)
||Development of Refractory Metal-based CCAs with Improved Mechanical Properties
||Stephan Laube, Steven Schellert, Alexander Kauffmann, Bronislava Gorr, Yolita Eggeler, Hans-Juergen Christ, Martin C. Heilmaier
|On-Site Speaker (Planned)
Refractory compositionally complex alloys (RCCA) are promising candidates for high-temperature structural applications. To achieve good mechanical performance at elevated temperatures, the proper formation of a strengthening phase is crucial. In order to mimic the microstructures of precipitation-strengthened Ni-based superalloys, we developed an A2 matrix alloy, 82(TaMoTi)-8Cr-10Al (at.%) with B2 particles that are formed by a precipitation reaction, namely by diffusion-controlled nucleation and growth. The Al content is crucial to obtain the proper reaction sequence. By adjusting Al concentration, the ordering temperature can be tailored to be congruent with the maximum temperature of the two-phase field as a first prerequisite. In order to reveal the distinct nature of phase separation sequence, i.e. nucleation and growth, atom probe tomography and electron microscopy techniques were utilized on samples that were annealed over orders of magnitude in time at temperatures beyond 800°C and the impact of coherent particle strengthening on mechanical properties is discussed.
||Planned: Metallurgical and Materials Transactions