Combining gradient structure and supersaturated solid solution to achieve superior mechanical properties in WE43 magnesium alloy

Wanting Sun, Bo Wu, Hui Fu, Xu Sheng Yang, Xiaoguang Qiao, Mingyi Zheng, Yang He, Jian Lu, San Qiang Shi

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

In this study, surface mechanical attrition treatment was employed to sucessfully produce a gradient nanostructured layer on WE43 magnesium alloy. X-ray diffraction, energy dispersive X-ray spectrometer, and high-resolution transmission electron microscope observations were mainly performed to uncover the microstructure evolution responsible for the refinement mechanisms. It reveals that the grain refinement process consists of three transition stages along the depth direction from the core matrix to the topmost surface layer, i.e., dislocation cells and pile-ups, ultrafine subgrains, and randomly orientated nanograins with the grain size of ~40 nm. Noticeably, the original Mg3RE second phase is also experienced refinement and then re-dissolved into the α-Mg matrix phase, forming a supersaturated solid solution nanostructured α-Mg phase in the gradient refined layer. Due to the cooperative effects of grain refinement hardening, dislocation hardening, and supersaturated solid-solution hardening, the gradient nanostructured WE43 alloy contributes to the ultimate tensile strength of ~435 MPa and ductility of ~11.0%, showing an extraordinary strain hardening and mechanical properties among the reported severe plastic deformation-processed Mg alloys. This work provides a new strategy for the optimization of mechanical properties of Mg alloys via combining the gradient structure and supersaturated solid solution.

Original languageEnglish
Pages (from-to)223-238
Number of pages16
JournalJournal of Materials Science and Technology
Volume99
DOIs
Publication statusPublished - 10 Feb 2022

Keywords

  • Gradient nanostructure
  • High strength and ductility
  • Mg-RE alloy
  • Strengthening mechanisms
  • Supersaturated solid solution
  • Surface mechanical attrition treatment

ASJC Scopus subject areas

  • Ceramics and Composites
  • Mechanics of Materials
  • Mechanical Engineering
  • Polymers and Plastics
  • Metals and Alloys
  • Materials Chemistry

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