Effects of volume fraction of Ni‐containing LPSO phase on mechanical and corrosion properties of Mg‐Gd‐Ni alloys

摘要

>Mg‐Gd‐Ni alloys with same Gd/Ni mole ratios but different volume fraction of Ni‐containing LPSO phase were prepared. The effects of the volume fraction of Ni‐containing LPSO phase on the mechanical and corrosion properties of Mg‐Gd‐Ni alloys were systematically investigated. It was found that the strength was remarkably enhanced but the plasticity was decreased with the increase of the volume fraction of Ni‐containing LPSO phase. The electro‐potential distribution characteristic shows that the Ni‐containing LPSO phase had a lower electro‐potential than the Mg matrix, which was related to the existence of Ni in LPSO phase. Consequently, Ni‐containing LPSO phase was preferentially eroded during micro‐galvanic corrosion. High volume fraction LPSO phases accelerated the corrosion rate of Mg‐Gd‐Ni alloy. The detailed corrosion mechanisms were discussed in the present study.