Comparative study of microstructure and mechanical properties of thermo-mechanically processed Al_{(0.2, 0.5)} CoCrFeNiMo_0.5 high-entropy alloys

ABSTRACT

The main objective of the present work is to produce Al_xCoCrFeNiMo_0.5 alloy through a wrought process. Al_xCoCrFeNiMo_0.5 high-entropy alloys with two different Al contents (x = 0.2 and 0.5) were prepared by vacuum arc melting followed by thermo-mechanical processing. Microstructural evolution was investigated after hot forging and subsequent homogenisation using XRD, SEM, and TEM. The final microstructure corresponding to Al_0.2 and Al_0.5 are BCT (sigma) in the FCC matrix and BCT (sigma) and ordered BCC together in the FCC matrix respectively. Room-temperature mechanical properties were investigated using uniaxial compression and hardness measurements. There is an apparent increase in strength and a decrease in ductility for the Al_0.5 alloy. However, a higher ductility was observed in Al_0.2 alloy with a compromised reduction in strength.

KEYWORDS:

• High-entropy alloy
• microstructure
• forging
• deformation
• fracture

Acknowledgments

The authors would like to acknowledge the financial support of the DST-FIST (grant no. SR/FST/ETI-421/2016) program for funding the FESEM-EBSD facility and Science and Engineering Research Board, Government of India (grant no. ECR/2017/001278) for financing the project. The authors also like to acknowledge Dr. Mithun Palit for helping in the alloy preparation.

Disclosure statement

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

Additional information

Funding

This work was supported by SERB-ECR: [Grant Number ECR/2017/001278]; DST-FIST: [Grant Number SR/FST/ETI-421/2016].