Recent observations of particulates in Nitinol

TitleRecent observations of particulates in Nitinol
Publication TypeJournal Article
Year of Publication2008
AuthorsShabalovskaya S, Anderegg J, Van Humbeeck J
Journal TitleMaterials Science and Engineering a-Structural Materials Properties Microstructure and Processing
Date PublishedMay
Type of ArticleProceedings Paper
ISBN Number0921-5093
Accession NumberISI:000255716100089
Keywordsalloys, biocompatibility, carbides, corrosion, inclusions, NiTi, oxides, SHAPE-MEMORY

In spite of 40 years of history of Nitinol, the issues regarding its inclusions have been poorly explored. In our brief studies, conducted within the projects on surface design using Auger, energy-dispersive X-ray spectroscopy and scanning electrons microscopy, we discovered that particulates in NiTi medical alloys were always based on Ti: either similar to Ti2NiO oxide, titanium dioxide, titanium carbide or oxidized titanium carbide. Nonmetallic particles were rather brittle, had various shapes and sizes, and revealed different solubility in chemical solutions. The matrix material surrounding inclusions showed a tendency to localized corrosion. It was hypothesized that release of inclusion debris in the human body due to corrosion might compromise biocompatibility of Nitinol. (C) 2007 Elsevier B.V. All rights reserved.

Alternate JournalMater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process.