Laser additively manufacturing of Al0.5CoCrFeNiTi0.5 high-entropy alloys with increased resistances to corrosion 3.5% NaCl and oxidation at 1000 °C

Conventionally arc-melted Al0.5CoCrFeNiTi0.5 is a high-entropy alloy (HEA) consisting of a major body-centered cube (BCC) phase and a minor face-centered cube (FCC) phase. Similar six-component dual-phase HEA was successfully manufactured by laser melting deposition (LMD) in the work. It was found that the Al0.5CoCrFeNiTi0.5 microstructure could be easily adjusted and controlled by changing the laser energy density (LED). Its gradual decrease helped to not only homogenize the FCC phase distribution over the BCC phase but also minimize the element concentration difference between the two phases. This microstructural evolution resulted in a significant increase of the as-deposited HEA in both resistances to corrosion in 3.5% NaCl and oxidation in air at 1000 degrees C. The LED-dependent microstructures and their relationships with the liquid and dry corrosion were interpreted.