Sealing of PEO Coated AZ91 Magnesium Alloy Using La-Based Solutions

Figure 7

Scanning electron micrographs (secondary electrons) of the surface and cross section of sealing coatings formed on AZ91 magnesium alloy with 12 g/l of La(NO₃)₃ with different treatment times and temperature: (a) 30°C, 10 min; (b) 30°C, 30 min; (c) 40°C, 10 min; (d) 40°C, 30 min; (e) 50°C, 10 min; (f) 50°C, 30 min.