Engineering heterogeneous microstructure by severe warm-rolling for enhancing strength-ductility synergy in eutectic high entropy alloys
Artikel i vetenskaplig tidskrift, 2019

The microstructure and mechanical properties of a (L12+B2) AlCoCrFeNi2.1 eutectic high entropy alloy (EHEA) processed by severe warm-rolling were investigated in the present work. The EHEA was successfully warm-rolled up to 90% reduction in thickness at 400 °C, 600 °C and 750 °C. Considerable differences in the microstructural evolution were identified during warm-rolling at the three temperatures. The L12 phase in the EHEA was disordered due to severe warm-rolling at 400 °C and 750 °C, while a predominantly ordered structure was retained in the EHEA warm-rolled at 600 °C. This anomalous behavior could be adequately explained by the sluggish ordering kinetics at lower deformation temperatures. The EHEA warm-rolled at 750 °C showed an extremely heterogeneous microstructure featured by retained lamellar regions comprising of B2 and FCC lamellae with dispersed B2 phase inside the FCC, whereas the non-lamellar regions showed a mixture of ultrafine to nanocrystalline disordered FCC, ordered B2 and Cr-rich σ phases. The non-lamellar regions were scarce and nearly absent in the EHEA 90% warm-rolled at 600 °C and 400 °C, respectively. The remarkably heterogeneous microstructure of EHEA warm-rolled at 750 °C resulted in outstanding strength-ductility combination with tensile strength ~1635 MPa and elongation to failure ~18%. The results indicated tremendous potential for achieving superior mechanical properties in heterogeneous EHEAs processed by severe warm-rolling.

Phase transformation


High entropy alloys


Mechanical properties


Rajasekhar Reddy Seelam

IIT Hyderabad

Shuhei Yoshida

Kyoto University

Upender Sunkari

IIT Hyderabad

Adrianna Lozinko

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Jithin Joseph

Deakin University

Rajib Saha

Tata Steel

Daniel Fabijanic

Deakin University

Sheng Guo

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Pinaki Prasad Bhattacharjee

IIT Hyderabad

Nobuhiro Tsuji

Kyoto University

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

0921-5093 (ISSN)

Vol. 764 138226


Annan materialteknik

Metallurgi och metalliska material





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