Surface morphology transformation and densification behaviour of conventionally sintered AlFeCoNiSi high entropy alloys

ABSTRACT

A preliminary study has been performed to understand the effect of pressureless sintering on the surface morphology of the AlFeCoNi alloy by the addition of the Si element. This study aims to determine the possibility of achieving the densification of high entropy alloy using the conventional sintering technique. The results indicate that the HEAs have a single-phase BCC structure even with the addition of Si. The thermodynamic simulation (CALPHAD) was used to predict the phase formation. The variation of crystallite sizes and lattice strains caused by sintering temperatures was also discussed. In addition, densification mechanisms occurring with the different sintering temperatures have been discussed. The formation of porosity was observed, however, the density of HEAs improved with increasing sintering temperature. Ultimately, it was suggested that the present HEAs required higher sintering temperatures and a longer time to achieve high density.

KEYWORDS:

• High-entropy alloy
• mechanical alloying
• sintering
• CALPHAD
• powder metallurgy

Acknowledgement

The authors would like to thank Dr. Vinod Kumar, Associate Professor at IIT Indore, and Mr. Sandeep Jain, Ph.D. scholar at IIT Indore also acknowledged for their help in thermodynamic simulation.

Disclosure statement

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

Authors contribution statement

Sheetal Kumar Dewangan: Investigation, Formal analysis, Writing – original draft. Cheenepalli Nagarjuna: Formal analysis, Writing – original draft.

Hansung Lee: Writing – original draft editing.

Ashutosh Sharma: Investigation, Formal analysis, Writing – review and editing. Byungmin Ahn: Conceptualisation, Investigation, Methodology, Resources, Formal analysis, Writing – review and editing.

‪Conflict of interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability

The data required to reproduce these findings cannot be shared at this time, as the research data are confidential.

Additional information

Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [Grant Number 2021R1A2C1005478].