| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1470853 | Corrosion Science | 2010 | 7 Pages |
Laser remelting was applied to plasma-sprayed Al–Si coating on magnesium alloy AZ91D to improve corrosion performance. Both salt spray testing and potentiodynamic polarization measurement in 3.5% NaCl solution indicated that laser-remelted Al–Si coating acquired better corrosion resistance than AZ91D and plasma-sprayed Al–Si coating. The decreasing order of the corrosion rates are AZ91D base metal, sprayed Al–Si coating and laser-remelted Al–Si coating. The fine Al–Si eutectic matrix in the laser-remelted microstructure contributed to the improved corrosion performance relative to the AZ91D and the plasma-sprayed coating. The predominant corrosion mechanisms in AZ91D, plasma-sprayed coating and laser-remelted coating are intra-granular corrosion, crevice corrosion and the combined pitting and galvanic corrosion, respectively.
Research highlights► Laser-remelting changes microstructure of Al–Si plasma-sprayed coating on AZ91D ► Laser-remelted Al–Si coating manifests better corrosion resistance ► Pitting and galvanic corrosion occur at α-Al dendrites of laser-remelted coating ► Refined Al–Si eutectic matrix contributes to the better corrosion resistance
