Mechanical alloying and spark plasma sintering of AlCrCuFeZn high entropy alloy

ABSTRACT

The AlCrCuFeZn multi-component high entropy alloy was synthesised by mechanical alloying and spark plasma sintering (SPS). Alloying behaviour, microstructure and phase stability were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). In the metastable as-milled condition, two disordered body centred cubic (BCC) phases were observed with crystallite size less than 40 nm. SPS was efficient in obtaining high densification, 91%, in the sintered condition. The structural evolution during the sintering occurred by the formation of two stable phases, one enriched in CuZn with Cu₅Zn₈-type structure, and another enriched in FeAlCr with a BCC structure. High hardness of 661 and 627 HV was obtained in the as-milled powder and SPS sintered sample, respectively.

KEYWORDS:

• High entropy alloys
• mechanical alloying
• spark plasma sintering

Acknowledgements

The authors would like to thank Professor Dr. A. A. Eiras - Department of Physics of the Federal University of São Carlos - for the spark plasma facility and his kind assistance. The authors acknowledge the financial support of CNPq (process number 446716 / 2014-6).

Disclosure statement

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

Additional information

Funding

The authors acknowledge the financial support of CNPq (process number 446716/2014-6).