J. Mater. Sci. Technol. ›› 2019, Vol. 35 ›› Issue (11): 2618-2624.DOI: 10.1016/j.jmst.2019.06.009

• Orginal Article • Previous Articles     Next Articles

High-performance hot-warm rolled Zn-0.8Li alloy with nano-sized metastable precipitates and sub-micron grains for biodegradable stents

Li Zhena, Shi Zhang-Zhib*(), Hao Yuana, Li Hua-Fanga, Liu Xue-Fengb, Volinsky Alex A.c, Zhang Hai-Junde, Wang Lu-Ninga**()   

  1. aBeijing Advanced Innovation Center for Materials Genome Engineering, State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
    bBeijing Laboratory of Metallic Materials and Processing for Modern Transportation, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
    cDepartment of Mechanical Engineering, University of South Florida, Tampa, FL, 33620, USA
    dDepartment of Interventional and Vascular Surgery, The Tenth People’s Hospital of Shanghai, Tongji University, Shanghai, 200072, China;
    eNational United Engineering Laboratory for Biomedical Material Modification, Branden Industrial Park, Qihe Economic & Development Zone, Dezhou, 251100, China
  • Received:2019-04-11 Online:2019-11-05 Published:2019-10-21
  • Contact: Shi Zhang-Zhi,Wang Lu-Ning
  • About author:

    1The authors equally contributed to this work.

Abstract:

Fabricated through a newly developed hot-warm rolling process, Zn-0.8Li (wt%) alloy has ideal strength and ductility far beyond the mechanical benchmark of materials for biodegradable stents. Precipitation of needle-like Zn in primary β-LiZn4 phase is observed in Zn-Li alloy for the first time. Orientation relationship between them can be described as [1-213]β//[2-1-10]Zn, (10-10)β about 4.5° from (0002)Zn. Zn grains with an average size of 640 nm exhibit strong basal texture, detected by transmission electron back-scatter diffraction. Li distribution is determined by three-dimensional atom probe, which reveals the formation of nano-sized metastable α-Li2Zn3 precipitates with a number density of 7.16 × 1022 m-3. The fine lamellar Zn + β-LiZn4 structure, sub-micron grains and the nano-sized precipitates contribute to the superior mechanical properties.

Key words: Zn-Li alloy, Mechanical properties, Three-dimensional atom probe, Precipitation, Recrystallization