The Estimation of Corrosion Behavior of NiTi and NiTiNb Alloys Using Dynamic Electrochemical Impedance Spectroscopy

Table 2

Impedance parameters of NiTi and NiTiNb alloys in physiological 0.9 wt% NaCl solution, at 37°C.

Sample	Imposed potential	𝑅1(kΩ cm^2)	10^5𝑄1(S/cm^2 𝑠^𝑛)	𝑛1	𝑅2(MΩ cm^2)	10^5𝑄2(S/cm^2 𝑠^𝑛)	𝑛2	𝑅3(Ω cm^2)	𝐿(H/cm^2)
NiTi	OCP	1.7	7.2	0.86	0.2	1.3	0.85	—	—
	Passive region	—	—	—	1.1	0.8	0.86	—	—
	Dissolution region	0.1	0.6	0.79	—	—	—	45	25
NiTiNb	OCP	21.5	2.3	0.88	0.6	1.1	0.86	—	—
	Passive region	—	—	—	4.1	0.6	0.88	—	—