Segregation-dislocation self-organized structures ductilize a work-hardened medium entropy alloy

Dislocations are the intrinsic origin of crystal plasticity. However, initial high-density dislocations in work-hardened materials are commonly asserted to be detrimental to ductility according to textbook strengthening theory. Inspired by the self-organized critical states of non-equilibrium complex systems in nature, we explored the mechanical response of an additively manufactured medium entropy alloy with segregation-dislocation self-organized structures (SD-SOS). We show here that when initial dislocations are in the form of SD-SOS, the textbook theory that dislocation hardening inevitably sacrifices ductility can be overturned. Our results reveal that the SD-SOS, in addition to providing dislocation…

• CU
  City University of Hong Kong

  Awards: 9509008, C1020-21G
• CF
  Croucher Foundation
• NN
  National Natural Science Foundation of China

  Awards: 2023A1515012703, 2023QNRC001, 52474425, 52474423
• SK
  State Key Laboratory of Solidification Processing
• NK
  National Key Research and Development Program of China
• FR
  Fundamental Research Funds for the Central Universities

  Award: G2022KY05109
• BA
  Basic and Applied Basic Research Foundation of Guangdong Province

  Award: 2023A1515012703