Role of alloyed Nd in the microstructure and atmospheric corrosion of as-cast magnesium alloy AZ91

•Corrosion rate of AZ91 significantly decreases with the addition of 0.5–1.0wt.% Nd.•Nd refines β-phase morphology.•Nd suppresses micro-galvanic couples between constituents.•Nd increases the amount of carbonates on the corrosion film. The influence of Nd on the atmospheric corrosion performance of...

Full description

Saved in:
Bibliographic Details
Published inCorrosion science Vol. 97; pp. 38 - 48
Main Authors Arrabal, R., Mingo, B., Pardo, A., Matykina, E., Mohedano, M., Merino, M.C., Rivas, A., Maroto, A.
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 01.08.2015
Subjects
A. Alloy
A. Magnesium
B. AFM
C. Atmospheric corrosion
A. Magnesium
B. AFM
A. Alloy
C. Atmospheric corrosion
Online AccessGet full text

Cover

More Information
Summary:•Corrosion rate of AZ91 significantly decreases with the addition of 0.5–1.0wt.% Nd.•Nd refines β-phase morphology.•Nd suppresses micro-galvanic couples between constituents.•Nd increases the amount of carbonates on the corrosion film. The influence of Nd on the atmospheric corrosion performance of AZ91 alloy was evaluated as per PV1210 standard. Additionally, immersion and electrochemical measurements were carried out. The beneficial effect of Nd is associated with: (i) suppressed galvanic corrosion between α-Mg and secondary phases, (ii) refined β-phase morphology and (iii) increased proportion of carbonates in the outer surface layer. In case of atmospheric corrosion, the role of β-phase is the least important factor out of the three. The optimum Nd content is 0.5wt.%. Further additions do not improve significantly the corrosion performance.
ISSN:0010-938X
1879-0496
DOI:10.1016/j.corsci.2015.04.004