Engineering heterogeneous microstructure by severe warm-rolling for enhancing strength-ductility synergy in eutectic high entropy alloys
Journal article, 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, Industrial and Materials Science, Materials and manufacture

Jithin Joseph

Deakin University

Rajib Saha

Tata Steel

Daniel Fabijanic

Deakin University

Sheng Guo

Chalmers, Industrial and Materials Science, Materials and manufacture

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

Subject Categories

Other Materials Engineering

Metallurgy and Metallic Materials

Areas of Advance

Materials Science



More information

Latest update