Heterogeneous structure-induced strength-ductility synergy by partial recrystallization during friction stir welding of a high-entropy alloy

Po-Ting Lin; Hung-Chi Liu; Po-Ying Hsieh; Cheng-Yu Wei; Che-Wei Tsai; Yutaka S. Sato; Shih-Che Chen; Hung-Wei Yen; Nian-Hu Lu; Chih-Hsuan Chen

Materials & Design (Jan 2021)

Heterogeneous structure-induced strength-ductility synergy by partial recrystallization during friction stir welding of a high-entropy alloy

Po-Ting Lin,
Hung-Chi Liu,
Po-Ying Hsieh,
Cheng-Yu Wei,
Che-Wei Tsai,
Yutaka S. Sato,
Shih-Che Chen,
Hung-Wei Yen,
Nian-Hu Lu,
Chih-Hsuan Chen

Affiliations

Po-Ting Lin: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan; High Entropy Materials Center, National Tsing Hua University, Hsinchu, Taiwan
Hung-Chi Liu: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
Po-Ying Hsieh: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
Cheng-Yu Wei: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
Che-Wei Tsai: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan; High Entropy Materials Center, National Tsing Hua University, Hsinchu, Taiwan; Corresponding author at: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan.
Yutaka S. Sato: Department of Materials Processing, Tohoku University, Sendai, Japan
Shih-Che Chen: Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan
Hung-Wei Yen: Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan
Nian-Hu Lu: Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
Chih-Hsuan Chen: Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan

Journal volume & issue: Vol. 197
p. 109238

Abstract

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To apply high-entropy alloys (HEAs) for extensive advanced structural uses, their welding properties should be well understood. In this study, Al0.3CoCrCu0.3FeNi HEA was butt welded by friction stir welding (FSW). The fine-grained partially recrystallized microstructure in the stir zone gave rise to a high tensile yield strength of 920 MPa with an elongation of 37%. By microstructural observation, the excellent mechanical properties of the stir zone material were attributed to the partially recrystallized heterogeneous structure, with which the synergetic strengthening improved the strength of the HEA with considerably less trade-off in its ductility. This unique phenomenon was unprecedented in any other friction-stir welded conventional alloys and was credited to the low stacking-fault energy and the high grain growth activation energy of the HEA. This work suggests that FSW can not only produce good HEA welds but serve as a special processing technique to enhance mechanical properties of HEAs.

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

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