Rapid screening alloying elements for improved corrosion resistance on the Mg(0001) surface using first principles
Chi Zhang1, Junsheng Wang1,2, Xin Li1
1School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China. junsheng.wang@bit.edu.cn.
Physical Chemistry Chemical Physics : PCCP
|November 26, 2021
Summary
Alloying elements significantly impact magnesium alloy corrosion resistance by altering surface stability and hydrogen adsorption. Yttrium doping enhances corrosion resistance, offering a new method for rapid screening of improved magnesium alloys.
Area of Science:
- Materials Science
- Electrochemistry
- Computational Materials Science
Background:
- Magnesium alloys exhibit poor corrosion resistance, hindering their widespread application.
- Corrosion is governed by magnesium's anodic dissolution and the hydrogen evolution reaction (HER) on the surface.
- Surface stability and hydrogen adsorption are critical factors influencing Mg alloy corrosion.
Purpose of the Study:
- To investigate the effects of various alloying elements (As, Ge, Cd, Zn, Ga, Al, Y) on Mg(0001) surface stability and hydrogen adsorption.
- To develop a comprehensive approach for evaluating how alloying elements influence Mg alloy corrosion resistance.
- To identify specific alloying elements that can enhance the stability and inhibit HER in Mg alloys.
Main Methods:
- First principles calculations were employed to study the Mg(0001) surface.
- A horizontally integrated approach assessed surface energy, vacancy formation energy, Bader charge, and electron density.
- Calculations evaluated the adsorption free energy of hydrogen atoms on different surface sites.
Main Results:
- Doped atoms significantly altered the Mg surface's atomic structure and electron transfer.
- Alloying elements modified the energy of atom detachment, hydrogen adsorption energy, and stable adsorption sites.
- Yttrium doping was found to notably increase the corrosion resistance of the Mg surface.
Conclusions:
- Alloying elements critically influence Mg surface properties, thereby regulating corrosion resistance.
- The study presents a novel method for rapidly screening alloying elements to improve Mg alloy stability.
- Inhibiting the hydrogen evolution reaction through strategic doping is key to enhancing Mg alloy performance.
