Details

Autor(en) / Beteiligte

• Wang, Liang
• Ding, Jun
• Chen, Songshen
• Jin, Ke
• Zhang, Qiuhong
• Cui, Jiaxiang
• Wang, Benpeng
• Chen, Bing
• Li, Tianyi
• Ren, Yang
• Zheng, Shijian
• Ming, Kaisheng
• Lu, Wenjun
• Hou, Junhua
• Sha, Gang
• Liang, Jun
• Wang, Lu
• Xue, Yunfei
• Ma, En

Titel

Tailoring planar slip to achieve pure metal-like ductility in body-centred-cubic multi-principal element alloys

Ist Teil von

• Nature materials, 2023-08, Vol.22 (8), p.950-957

Ort / Verlag

England: Nature Publishing Group

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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.