A quantitative study on planar mechanical anisotropy of a Mg-2Zn-1Ca alloy. (20th May 2022)

• Record Type: Journal Article
• Authors: Huang, Xinde; Xin, Yunchang; Cao, Yu; Huang, Guangjie; Li, Wei
• Is Part Of: Journal of materials science & technology. Volume 109(2022)
• Page Start: 30
• Page End: 48
• Publication Date: 2022-05-20
• Subjects: Mg alloy -- Deformation -- Yield strength -- Anisotropy; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2021.07.051
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: The planar mechanical anisotropy exhibits a grain size independence. A new method for quantitative analysis on the planar mechanical anisotropy is proposed. To reduced planar yield anisotropy, the tilting angle and direction of basal poles away from ND are crucial parameters. 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, σ 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 σ 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.