Influence of specific second phases on corrosion behaviors of Mg-Zn-Gd-Zr alloys

[Display omitted] •A comparatively considerable corrosion resistance is achieved in extruded Mg-3Zn-11Gd-0.6Zr alloy.•Lower potential differences between Mg-Zn-Gd ternary phases and Mg matrix are beneficial to corrosion behavior.•A wide distribution of compact X-phase lamella acts as corrosion barri...

Full description

Saved in:
Bibliographic Details
Published in:Corrosion science 2020-04, Vol.166, p.108419, Article 108419
Main Authors: Yin, Siqi, Duan, Wenchao, Liu, Wenhong, Wu, Liang, Yu, Jiamin, Zhao, Zilong, Liu, Min, Wang, Ping, Cui, Jianzhong, Zhang, Zhiqiang
Format: Article
Language:English
Subjects:
A. Magnesium
B. EIS
B. Weight loss
C. Anodic dissolution
C. Pitting corrosion
Continuous extrusion
Corrosion
Corrosion effects
Corrosion mechanisms
Corrosion resistance
Corrosion resistant alloys
Gadolinium
Galvanic corrosion
Immersion tests (corrosion)
Magnesium
Phases
Pressure casting
Submerging
Ternary systems
Uniform attack (corrosion)
Zinc
Zirconium base alloys
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:[Display omitted] •A comparatively considerable corrosion resistance is achieved in extruded Mg-3Zn-11Gd-0.6Zr alloy.•Lower potential differences between Mg-Zn-Gd ternary phases and Mg matrix are beneficial to corrosion behavior.•A wide distribution of compact X-phase lamella acts as corrosion barrier during corrosion.•X-phase could act as an anode during micro-galvanic corrosion with W-phase. The corrosion behavior and mechanism of as-cast and as-extruded Mg-Zn-Gd-Zr alloys with specific ternary phases are investigated using scanning electron microscope (SEM), scanning Kelvin probe force microscope (SKPFM), immersion and electrochemical tests. Lamellar X-Mg12GdZn, net-like W-Mg3Gd2Zn3 and strip-like I-Mg3Zn6Gd phases form successively. The eutectic W-phase owns the highest potential difference of 120 mV with Mg matrix, accelerating micro-galvanic corrosion. Continuously distributed and undersized I-phase leads to uniform corrosion. The as-extruded Mg-3Zn-11Gd-0.6 Zr alloy exhibits superior corrosion resistance, due to the relatively low potential difference between X-phase and matrix, the corrosion barrier effect and typical {0002} texture components.
ISSN:0010-938X
1879-0496
DOI:10.1016/j.corsci.2019.108419