AVS 45th International Symposium
    Biomaterial Interfaces Group Monday Sessions
       Session BI-MoP

Paper BI-MoP5
Effects of Surface Finish on the Corrosion of NiTi Shape Memory Alloy

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Biomaterial Interfaces Poster Session
Presenter: S. Trigwell, VG Scientific
Authors: S. Trigwell, VG Scientific
G. Selvaduray, San Jose State University
Correspondent: Click to Email
NiTi (nitinol) alloys have become very attractive to biomedical applications because of their unique shape memory and superelastic properties. Due to the high Ni content of the alloy (up to 55%), concern has been expressed as to its biocompatibility. Nickel is known to cause toxic reactions in the body and be a possible carcinogen in cases of long term exposure, such as in implants. In this study, coupons of an equiatomic alloy were prepared by four methods (mechanically polishing, electropolishing, chemically etching, and plasma etching) to produce various levels of roughness and surface chemistry, as examined by AFM, SEM, XPS, and AES. The corrosion current (rate) for each finish was determined in Hank's Balanced Salt Solution at 37°C. The correlation between surface finish and corrosion susceptibility was determined that may be important in the preparation of NiTi for biomedical applications.