Enhanced strength and corrosion resistance of Mg-Gd-Y-Zr alloy with ultrafine grains

• Published in: Materials letters 2018-02, Vol.213, p.274-277
• Main Authors: Wan, Yingchun, Xu, Shiyuan, Liu, Chuming, Gao, Yonghao, Jiang, Shunong, Chen, Zhiyong
• Format: Article
• Language: English
• Subjects: Corrosion; Corrosion currents; Corrosion effects; Corrosion resistance; Corrosion resistant alloys; Forging; Gadolinium; Grain boundaries; Magnesium base alloys; Materials science; Mg-Gd-Y-Zr alloy; Microstructure; Strength; Temperature; Yttrium; Zirconium
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2017.11.096

[Display omitted] •UFG Mg alloy was fabricated by forging at room temperature.•Improvements in strength and corrosion resistance were realized.•The yield strength increment coincides well with the Bailey-Hirsch equation.•UFG structure is responsible for the enhanced corrosion resistance. Simultaneous improvements in strength and corrosion resistance of Mg-Gd-Y-Zr alloy were realized through forging at room temperature with formation of ultrafine grained (UFG) structure. Compared with its coarse grained (CG) counterpart, the UFG sample exhibits an enhancement of 211 MPa (103%) in yield strength and a reduction of 0.644 × 10−5 A/cm2 (25%) in corrosion current density. Effect of microstructure on the mechanical property was quantitatively investigated, revealing a good coincidence of the experimental result with the calculated one based on Bailey-Hirsch equation. The improvement in corrosion resistance is attributed to the formation of sub-grain boundaries.