Effect of carbon on microstructure and mechanical properties of Fe₃₆Mn₃₆Ni₉Cr₉Al₁₀ high-entropy alloys

Abstract

The effect of C-alloying on phase constituent, microstructure and mechanical behaviour of a novel Co-free (Fe₃₆Mn₃₆Ni₉Cr₉Al₁₀)_100-xC_x (x = 0, 1.5, 2.5, 3.5, 5, 6) low-cost high entropy alloy (HEA) system was investigated. Addition of carbon promoted the transformations of BCC and B2 phase in the original C-free HEA into FCC phase. At a carbon content of 2.5 at.-% and beyond, hardly BCC phase constituent can be obtained. Optimised mechanical properties with a yield strength of 387 MPa, tensile strength of 741 MPa along with excellent ductility of 57% were achieved at a carbon content of 2.5 at.-%. The improvement in mechanical properties of the (Fe₃₆Mn₃₆Ni₉Cr₉Al₁₀)_97.5C_2.5 HEA can be ascribed to enhance the work hardening ability originated from microband-induced plasticity effect.

KEYWORDS:

• High entropy alloy
• carbon alloying
• phase transition
• microband-induced plasticity

Acknowledgements

This study was supported by National Natural Science Foundation of China (51671150, 51901167 and 51931005). Shaanxi Outstanding Youth fund (2020JC-49) and Youth Innovation Team of University in Shaanxi Province.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by National Natural Science Foundation of China [grant number 51671150, grant number 51901167 and grant number 51931005 ]; Shaanxi Outstanding Youth Fund [2020JC-49] and Youth Innovation Team of University in Shaanxi Province.