Surface modification techniques can offer means for changing properties of materials on or near the surface. The Ti ions and Zr ions were implanted into the Mg-1.0 wt.% Ca-1.0 wt.% Zn alloy surface respectively at the dose of 5×10¹⁶ ions/cm², 1.0×10¹⁷ ions/cm², and 1.5×10¹⁷ the ions/cm² by metal vapour vacuum arc (MEVVA) ion implantation device to improve the mechanical properties and the corrosion resistance of the alloy.

EDS and XPS analysis results indicate that the surface element content of the alloy increases with the ion implantation dose. Further, the superficial nanometer indentation test result confirms that the ion implantation improves the surface hardness and the modulus of the alloy at a certain degree. It is found that the surface hardness and modulus of the Zr-implanted alloy are higher than these of Ti-implanted one. Three electrode system tests indicate that the polarization resistance of the Mg-1.0 wt.% Ca-1.0 wt.% Zn alloy by ion implantation increases. Especially the polarization resistance of the alloy implanted Zr at dose of 1 × 10¹⁷ ions/cm² increases by 2.3 times. The corrosion morphology of the alloy immersed in SBF for 72 h shows that the corrosion mechanism of the alloy is pitting. Ion-implanted alloy corrosion pits are small and scattered. Therefore the corrosion rate of alloys is reduced by ion implantation and the anti-corrosive performance is enhanced.

As a surface modification method, ion implantation plays an important role in improving the mechanical properties and the corrosion resistance of the Mg-1.0 wt.%Ca-1.0 wt.%Zn alloy.

 

Gao Zhi Fang*, School of Materials Science and Engineering, Tianjin University, China
Lihe Mao, School of Materials Science and Engineering, Tianjin University, China
Yizao Wan, School of Materials Science and Engineering, Tianjin University, 

*presenting author