A preliminary investigation into the microscopic depassivation of passive titanium implant materials in vitro

Abstract

A sensitive electrochemical technique has been used to examine the passive state of titanium-based materials in Ringer's physiological solution. At ambient temperature, the alloy Ti-6AI-4V shows transient microscopic breakdown of the passive state induced by the presence of chloride ions, and enhanced by increased acidity. These breakdown events involve highly localized depassivation of the passive surface followed by repassivation. Under similar experimental conditions no breakdown of passive titanium was detected.

Special modes of corrosion under physiological and simulated physiological conditions

“…Metastable pitting corrosion has been quite widely studied for stainless steels, but much less for biomedical implant materials. For Ti, metastable pitting has been reported to take place in bromide solutions [45], and also in physiological media [44,[46][47][48]. Metastable pitting activity was higher for the Ti-Al-V alloy than for pure Ti.…”

Investigation of processing effects on the corrosion resistance of Ti20Mo alloy in saline solutions

“…Two different surface conditions with major changes in surface roughness were thus produced. Since chloride ions are known to promote instabilities and eventual local breakdown of the protecting passive layers formed on Ti-based biomaterials [25][26][27][28][29], a saline solution was chosen as the test environment. Conventional electrochemical and scanning electrochemical techniques were employed to evaluate the stability and reactivity of the protective oxide layers formed on the surface of the alloys.…”

Improvement of the corrosion resistance and structural and mechanical properties of a titanium base alloy by thermo‐mechanical processing

“…The cyclic potentiodynamic polarization 34–36 was carried out beginning from −0.5 to +2.0 V ( vs . saturated calomel electrode – SCE) using a scan rate of 1 mV/s.…”