J. Mater. Sci. Technol. ›› 2022, Vol. 97: 20-28.DOI: 10.1016/j.jmst.2021.04.034

• Research Article • Previous Articles     Next Articles

Efficient rejuvenation of heterogeneous {[(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4}99.9Cu0.1 bulk metallic glass upon cryogenic cycling treatment

Siyi Dia, Qianqian Wanga, Yiyuan Yanga, Tao Lianga, Jing Zhoua, Lin Sub, Kuibo Yinb, Qiaoshi Zenga, Litao Sunb, Baolong Shena,c,*   

  1. aSchool of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing, 211189, China
    bSEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing, 210096, China
    cInstitute of Massive Amorphous Metal Science, China University of Mining and Technology, Xuzhou, 221116, China
  • Received:2021-02-09 Revised:2021-04-06 Accepted:2021-04-15 Published:2021-06-17 Online:2021-06-17
  • Contact: Baolong Shen
  • About author:*

Abstract:

The effects of cryogenic thermal cycling on deformation behaviour and structural variation of {[(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4}99.9Cu0.1 bulk metallic glass (BMG) were studied and compared with Cu-free [(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4 BMG. After thermal-cycled treatment between 393 K and cryogenic temperature, the {[(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4}99.9Cu0.1 BMG obtained a plastic strain of 7.4% combined with a high yield strength of 4350 MPa. The excellent soft magnetic properties were maintained after CTC treatment. The minor addition of Cu element results in an initial nano-sized heterogeneity in the matrix, which facilitates the rejuvenation process during thermal cycling, and brings to a low optimal thermal temperature of 393 K, making the {[(Fe0.5Co0.5)0.75B0.2Si0.05]96Nb4}99.9Cu0.1 BMG more attractive in industrial application. During thermal cycling, the formation of more soft regions leads to the increase of structural heterogeneities, which is beneficial to the initiation of shear transition zones and the formation of multiple shear bands, and thus results in the enhancement of plasticity. This study links the subtle variation of specific structure with macroscopic mechanical properties, and provides a new insight of composition selection for cryogenic thermal cycling treatment.

Key words: Bulk metallic glass, Plasticity, Cryogenic thermal cycling, Rejuvenation, Structural heterogeneity