Effects of surface treatment on the surface chemistry of NiTi alloy for biomedical applications

✍ Scribed by Trigwell, S.; Hayden, R. D.; Nelson, K. F.; Selvaduray, G.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 397 KB
• Volume: 26
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199806)26:7<483::aid-sia388>3.0.co;2-5

✦ Synopsis

Alloys of NiTi have gained popularity in biomedical applications ; however, Ni is known to cause toxic and allergic reactions in the body, and concerns have been expressed regarding the materialÏs biocompatibility. In this study, coupons of equiatomic NiTi were prepared by four methods, namely, mechanically polishing to a mirror Ðnish, electropolishing, chemical etching and argon plasma etching, to produce various levels of roughness, and then examined by atomic force microscopy (AFM), XPS and AES. The resulting surface chemistry depended upon the method of preparation and was found not to be a function of surface roughness. The mechanically polished samples, although having the smoothest surface, showed the highest level of Ni in the near-surface region. The other preparation methods produced surfaces that were predominantly with the electropolished surfaces showing the TiO 2 , next smoothest surface and the least Ni in the near-surface region. The correlation between method of preparation, surface roughness and surface chemistry may be important in the preparation of NiTi for biomedical applications.