Surface hardening of CrCoFeNi high-entropy alloys via Al laser alloying

Abstract

Undeformed face-centred cubic (FCC) high-entropy alloys (HEAs) always possess excellent plasticity but low hardness. In this work, Al alloying on the surface of a CrCoFeNi FCC HEA is realized by laser alloying technique. An Al_1.5CoCrFeNi body-centred cubic (BCC) HEA is in-situ generated on the surface of the FCC HEA. The well-bonding BCC HEA layer possesses a hardness as high as 536 HV. The hard surface results in a much lower wear rate of the Al-alloyed specimen than the pristine specimen. This study provides a simple strategy to harden the FCC HEAs by in-situ formation of BCC HEA through laser alloying.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

A laser alloying technology to harden CrCoFeNi FCC HEA by in-situ formation of BCC HEA.

KEYWORDS:

• Surface hardening
• laser alloying
• CrCoFeNi
• high-entropy alloy

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Disclosure statement

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

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 11725210] and the Fundamental Research Funds for the Central Universities [grant number 2018XZZX001-05].