Effect of surface treatment of NiTi alloy on its corrosion behavior in Hanks' solution

Copyright 2002 Wiley Periodicals, Inc..

The effect of surface modification of NiTi shape memory alloy on its corrosion behavior in Hanks' solution was determined. The near-equi-atomic super elastic NiTi (Ni 55.8 wt %) alloy used for this study was provided by Memry USA. The surfaces of heat-treated samples were modified by mechanical polishing (MP), electropolishing (EP), and electropolishing followed by chemical passivation (CP). As-heat-treated samples with straw-colored oxide finishes (SCO) and blue-colored oxide finishes (BO) also were included in the study. Surface analysis was performed using auger electron spectroscopy (AES), atomic force microscopy (AFM), and contact angle measurements (CAM). It was shown that surface roughness increased in the order CP < EP < SCO < BO < MP. The nickel release within the five groups of NiTi samples, as determined by atomic absorption spectrophotometry, reduced in time over the measured period. The level of Ni ions released over a 25-day immersion period was highest in the SCO sample (0.002 microg/day). This Ni level is negligible compared with the daily intake of Ni in an ordinary diet. The auger electron spectroscopy (AES) analyses indicated that before immersion in Hanks' physiologic solution, the main surface composition of all the samples was titanium and nickel, with a small amount of oxygen, carbon, and sulphur as contaminants. And the surface oxide thickness of the different samples increased in the order CP < EP < MP < BO < SCO. On the other hand, for the electrodes treated under the same conditions, the mean breakdown potential value decreased in the order BO > MP > CP > EP > SCO while the corrosion current density and rate increased in the order CP < SCO < EP < BO < MP.

Medienart:

Artikel

Erscheinungsjahr:

2002

Erschienen:

2002

Enthalten in:

Zur Gesamtaufnahme - volume:61

Enthalten in:

Journal of biomedical materials research - 61(2002), 3 vom: 05. Sept., Seite 339-45

Sprache:

Englisch

Beteiligte Personen:

Cissé, O [VerfasserIn]
Savadogo, O [VerfasserIn]
Wu, M [VerfasserIn]
Yahia, L'H [VerfasserIn]

Themen:

7OV03QG267
Alloys
D1JT611TNE
Hanks Balanced Salt Solution
Isotonic Solutions
Journal Article
Nickel
Titanium

Anmerkungen:

Date Completed 01.08.2003

Date Revised 31.03.2022

published: Print

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM11984365X