Microstructural stability and properties of Al1.2CrCuFeNi2 dual-phase high entropy alloy

The microstructural stability and mechanical properties of novel Al1.2CrCuFeNi2 dual-phase high entropy alloy (HEA) were investigated. The as-cast alloy was composed of a uniform near-eutectic structure consisting of Ni-Al rich B2 matrix and Cr-Fe rich BCC spherical phases (mean grain size:-100 nm). Annealing at 1000 degrees C results in the precipitation of ultrafine particles and transformation from spherical phase to needle shaped structure. The as-cast HEA has an excellent combination of super yield strength (-1326 MPa), fracture strength (-1762 MPa) and plastic strain (-24 %). After annealing, the compressive yield strength and fracture strength increase by -18 % and -13 %, respectively. This is mainly ascribed to the precipitation strengthening of ultrafine particles and the significant crystal lattice distortion strengthening in HEA. Besides, Vickers hardness increased from 548 HV to 612 HV implying that the Al1.2CrCuFeNi2 HEA projects excellent tempering softening resistant.

Automated summary

The microstructural stability and mechanical properties of a novel Al1.2CrCuFeNi2 dual-phase high entropy alloy were studied. The alloy exhibited a uniform near-eutectic structure composed of Ni-Al rich B2 matrix and Cr-Fe rich BCC spherical phases with an average grain size of about 100 nm. After annealing at 1000 degrees C, the alloy experienced precipitation of ultrafine particles and transformation from spherical to needle-like structure. The as-cast and annealed alloys demonstrated impressive combinations of yield strength, fracture strength, and plastic strain, and the hardness was also significantly improved after annealing, indicating excellent tempering softening resistance of the alloy.