Dislocation network in additive manufactured steel breaks strength–ductility trade-off

Research output: Contribution to journalArticlepeer-review

Authors

  • Leifeng Liu
  • Qingqing Ding
  • Yuan Zhong
  • Jing Wu
  • Jixue Li
  • Ze Zhang
  • Qian Yu
  • Zhijian Shen

Colleges, School and Institutes

Abstract

Most mechanisms used for strengthening crystalline materials, e.g. introducing crystalline interfaces, lead to the reduction of ductility. An additive manufacturing process – selective laser melting breaks this trade-off by introducing dislocation network, which produces a stainless steel with both significantly enhanced strength and ductility. Systematic electron microscopy characterization reveals that the pre-existing dislocation network, which maintains its configuration during the entire plastic deformation, is an ideal “modulator” that is able to slow down but not entirely block the dislocation motion. It also promotes the formation of a high density of nano-twins during plastic deformation. This finding paves the way for developing high performance metals by tailoring the microstructure through additive manufacturing processes.

Details

Original languageEnglish
Pages (from-to)354-361
JournalMaterials Today
Volume21
Issue number4
Early online date6 Dec 2017
Publication statusPublished - May 2018