Table 2.

Corrosion potential and corrosion current density of samples with different electrochemical etching times.

Electrochemical Etching Time (min)	Ecorr (V)	Icorr (A cm−2)	η (%)
0	−0.472	1.080 × 10−5	-
7	−0.370	1.376 × 10−6	87.3
15	−0.280	3.920 × 10−8	99.6
22	−0.415	2.160 × 10−6	80.0