Simultaneous Strength-Ductility Enhancement of a Nano-Lamellar AlCoCrFeNi2.1 Eutectic High Entropy Alloy by Cryo-Rolling and Annealing
Artikel i vetenskaplig tidskrift, 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.

Författare

T. Bhattacharjee

Kyoto University

I. S. Wani

IIT Hyderabad

Saad Ahmed Sheikh

Chalmers, Industri- och materialvetenskap, Material och tillverkning

I. T. Clark

Scienta Omicron

T. Okawa

Scienta Omicron

Sheng Guo

Chalmers, Industri- och materialvetenskap, Material och tillverkning

P. P. Bhattacharjee

IIT Hyderabad

N. Tsuji

Kyoto University

Scientific Reports

2045-2322 (ISSN)

Vol. 8 3276

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Annan materialteknik

Metallurgi och metalliska material

DOI

10.1038/s41598-018-21385-y