Simultaneous Strength-Ductility Enhancement of a Nano-Lamellar AlCoCrFeNi2.1 Eutectic High Entropy Alloy by Cryo-Rolling and Annealing
Journal article, 2018

Nano-lamellar (L1 2 + B2) AlCoCrFeNi 2.1 eutectic high entropy alloy (EHEA) was processed by cryo-rolling and annealing. The EHEA developed a novel hierarchical microstructure featured by fine lamellar regions consisting of FCC lamellae filled with ultrafine FCC grains (average size ∼200-250 nm) and B2 lamellae, and coarse non-lamellar regions consisting of ultrafine FCC (average size ∼200-250 nm), few coarse recrystallized FCC grains and rather coarse unrecrystallized B2 phase (∼2.5 μm). This complex and hierarchical microstructure originated from differences in strain-partitioning amongst the constituent phases, affecting the driving force for recrystallization. The hierarchical microstructure of the cryo-rolled and annealed material resulted in simultaneous enhancement in strength (Yield Strength/YS: 1437 ± 26 MPa, Ultimate Tensile Strength/UTS: 1562 ± 33 MPa) and ductility (elongation to failure/e f ∼ 14 ± 1%) as compared to the as-cast as well as cold-rolled and annealed materials. The present study for the first time demonstrated that cryo-deformation and annealing could be a novel microstructural design strategy for overcoming strength-ductility trade off in multiphase high entropy alloys.

Author

T. Bhattacharjee

Kyoto University

I. S. Wani

IIT Hyderabad

Saad Ahmed Sheikh

Chalmers, Industrial and Materials Science, Materials and manufacture

I. T. Clark

Scienta Omicron

T. Okawa

Scienta Omicron

Sheng Guo

Chalmers, Industrial and Materials Science, Materials and manufacture

P. P. Bhattacharjee

IIT Hyderabad

N. Tsuji

Kyoto University

Scientific Reports

2045-2322 (ISSN)

Vol. 8 1 3276

Subject Categories

Manufacturing, Surface and Joining Technology

Other Materials Engineering

Metallurgy and Metallic Materials

DOI

10.1038/s41598-018-21385-y

More information

Latest update

4/5/2018 1