摘要
The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.
采用电化学控制下的原位观察和原位原子力显微镜研究Mg-(7,9)Al-1Fe-x Nd合金在电解液环境下的局部微电偶腐蚀过程及动力学信息。结果表明:合金中富Nd相的形成导致电位差从~400mV(AlFe3/α-Mg)降低到~220 mV(富Nd相/α-Mg),使阴极相周围腐蚀产物减少、微尺度区域腐蚀电流密度降低。添加Nd显著提高了材料的耐蚀性能,主要归因于第二相与基体之间微电偶腐蚀的抑制。最后,根据原位观察和电化学结果讨论了Mg-(7,9)Al-1Fe-x Nd合金的腐蚀机理。
基金
financial support from the National Natural Science Foundation of China(No.51961026)。
