J. Mater. Sci. Technol. ›› 2022, Vol. 109: 30-48.DOI: 10.1016/j.jmst.2021.07.051

• Research Article • Previous Articles     Next Articles

A quantitative study on planar mechanical anisotropy of a Mg-2Zn-1Ca alloy

Xinde Huanga, Yunchang Xinb,*(), Yu Caoa, Guangjie Huanga,*(), Wei Lia   

  1. aSchool of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
    bKey Laboratory for Light-weight Materials, Nanjing Tech University, Nanjing 210009, China
  • Received:2021-05-18 Revised:2021-07-14 Accepted:2021-07-20 Published:2021-10-28 Online:2021-10-28
  • Contact: Yunchang Xin,Guangjie Huang
  • About author:gjhuang@cqu.edu.cn (G. Huang).
    * E-mail addresses: ycxin@cqu.edu.cn (Y. Xin),

Abstract:

A TD-tilted basal texture in Mg alloys often generates a strong planar mechanical anisotropy. Unfortunately, there has been not a quantitative study on this issue. In the present study, the mechanisms for the anisotropy of tensile yield strength in RD-TD plane were quantitatively studied for a Mg-2Zn-1Ca alloy with different grain sizes and textures. Here, RD and TD refer to the rolling direction and transverse direction of the plate. The results show that there is a strong planar yield anisotropy (∼24 ± 5 MPa), regardless of grain size, while this yield anisotropy is absent in texture with a circular distribution of basal poles. The examination of microstructure and X-ray diffraction analysis reveals that, beside basal slip as the predominant mode under both RD-tension and TD-tension, prismatic slip in RD-tension and both prismatic slip and extension twinning in TD-tension are also important. The parameters of Hall-Petch relation are also used to further analyze the mechanism for yield anisotropy. The changeable intercept, ${{\sigma }_{0}}$, and invariant Hall-Petch slope, k, between RD-tension and TD-tension are rationalized accounting for this anisotropy. The reasons why there are different ${{\sigma }_{0}}$ and similar k between TD-tension and RD-tension are quantitively discussed. At last, a texture design for decreasing the planar yield anisotropy is given.

Key words: Mg alloy, Deformation, Yield strength, Anisotropy