Microstructure evolution of Al0.6CoCrFeNi high entropy alloy powder prepared by high pressure gas atomization
(1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China;
2. National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing Institute of Technology, Beijing 100081, China;
3. College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China)
Abstract: The influence of cooling rate on the microstructure of Al0.6CoCrFeNi high entropy alloy (HEA) powders was investigated. The spherical HEA powders (D50≈78.65 μm) were prepared by high pressure gas atomization. The different cooling rates were achieved by adjusting the powder diameter. Based on the solidification model, the relationship between the cooling rate and the powder diameter was developed. The FCC phase gradually disappears as particle size decreases. Further analysis reveals that the phase structure gradually changes from FCC+BCC dual-phase to a single BCC phase with the increase of the cooling rate. The microstructure evolves from planar crystal to equiaxed grain with the cooling rate increasing from 3.19×104 to 1.11×106 K/s.
Key words: Al0.6CoCrFeNi; high entropy alloy; high pressure gas atomization; spherical powder; microstructure; cooling rate