TY - JOUR
T1 - Tailoring planar slip to achieve pure metal-like ductility in body-centred-cubic multi-principal element alloys
AU - Wang, Liang
AU - Ding, Jun
AU - Chen, Songshen
AU - Jin, Ke
AU - Zhang, Qiuhong
AU - Cui, Jiaxiang
AU - Wang, Benpeng
AU - Chen, Bing
AU - Li, Tianyi
AU - Ren, Yang
AU - Zheng, Shijian
AU - Ming, Kaisheng
AU - Lu, Wenjun
AU - Hou, Junhua
AU - Sha, Gang
AU - Liang, Jun
AU - Wang, Lu
AU - Xue, Yunfei
AU - Ma, En
N1 - Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2023/8
Y1 - 2023/8
N2 - Uniform tensile ductility (UTD) is crucial for the forming/machining capabilities of structural materials. Normally, planar-slip induced narrow deformation bands localize the plastic strains and hence hamper UTD, particularly in body-centred-cubic (bcc) multi-principal element high-entropy alloys (HEAs), which generally exhibit early necking (UTD < 5%). Here we demonstrate a strategy to tailor the planar-slip bands in a Ti-Zr-V-Nb-Al bcc HEA, achieving a 25% UTD together with nearly 50% elongation-to-failure (approaching a ductile elemental metal), while offering gigapascal yield strength. The HEA composition is designed not only to enhance the B2-like local chemical order (LCO), seeding sites to disperse planar slip, but also to generate excess lattice distortion upon deformation-induced LCO destruction, which promotes elastic strains and dislocation debris to cause dynamic hardening. This encourages second-generation planar-slip bands to branch out from first-generation bands, effectively spreading the plastic flow to permeate the sample volume. Moreover, the profuse bands frequently intersect to sustain adequate work-hardening rate (WHR) to large strains. Our strategy showcases the tuning of plastic flow dynamics that turns an otherwise-undesirable deformation mode to our advantage, enabling an unusual synergy of yield strength and UTD for bcc HEAs.
AB - Uniform tensile ductility (UTD) is crucial for the forming/machining capabilities of structural materials. Normally, planar-slip induced narrow deformation bands localize the plastic strains and hence hamper UTD, particularly in body-centred-cubic (bcc) multi-principal element high-entropy alloys (HEAs), which generally exhibit early necking (UTD < 5%). Here we demonstrate a strategy to tailor the planar-slip bands in a Ti-Zr-V-Nb-Al bcc HEA, achieving a 25% UTD together with nearly 50% elongation-to-failure (approaching a ductile elemental metal), while offering gigapascal yield strength. The HEA composition is designed not only to enhance the B2-like local chemical order (LCO), seeding sites to disperse planar slip, but also to generate excess lattice distortion upon deformation-induced LCO destruction, which promotes elastic strains and dislocation debris to cause dynamic hardening. This encourages second-generation planar-slip bands to branch out from first-generation bands, effectively spreading the plastic flow to permeate the sample volume. Moreover, the profuse bands frequently intersect to sustain adequate work-hardening rate (WHR) to large strains. Our strategy showcases the tuning of plastic flow dynamics that turns an otherwise-undesirable deformation mode to our advantage, enabling an unusual synergy of yield strength and UTD for bcc HEAs.
UR - http://www.scopus.com/inward/record.url?scp=85152368896&partnerID=8YFLogxK
U2 - 10.1038/s41563-023-01517-0
DO - 10.1038/s41563-023-01517-0
M3 - Article
C2 - 37037961
AN - SCOPUS:85152368896
SN - 1476-1122
VL - 22
SP - 950
EP - 957
JO - Nature Materials
JF - Nature Materials
IS - 8
ER -