Fig. 5: High magnification in situ OM observations of the LZ91 alloy immersed in 3.5 wt% NaCl solution.

a Before immersion and after being immersed for b 5 min, c 2 h, d 6 h, e 13 h 20 min, f 13 h 30 min, and g 13 h 45 min. h After immersed for 24 h, the LZ91 alloy was removed from the solution.