Electrochemical and corrosion behaviors of the wrought Mg–Y–Zn based alloys with high Y/Zn mole ratios
Xuan Liu, Zijian Zhu, Jilai Xue
Abstract
The electrochemical behaviors and corrosion resistance of the wrought Mg–Y–Zn based alloys with high Y/Zn mole ratio have been investigated in details. The results show that the corrosion resistance of the investigated Mg–Y–Zn based alloys are dependent on the modified arrangement of LPSO phase by adjusting Y/Zn mole ratios. Increasing the Y/Zn mole ratio not only greatly decreases the size of LPSO phase plates, but also leads to the precipitation of Mg24Y5 phase. The corrosion rate of Mg–Y–Zn based alloys greatly increases from 7.4 mg·cm−2·day−1 to 11.3 mg·cm−2·day−1 with increasing the Y/Zn mole ratio up to 3. It should be attributed to the decreasing size of LPSO phase plates as cathodes, further increasing the hydrogen evolution kinetics. The related corrosion mechanism is discussed in details.