TY - JOUR

T1 - Corrosion fatigue behavior of a biocompatible ultrafine-grained niobium alloy in simulated body fluid

AU - Rubitschek, F.

AU - Niendorf, T.

AU - Karaman, I.

AU - Maier, H. J.

N1 - Funding information: Financial support from Deutsche Forschungsgemeinschaft and from National Science Foundation—International Materials Institute Program through Grant No. DMR 08-044082 , Office of Specific Programs, Division of Materials Research, Arlington, VA, is gratefully acknowledged.

PY - 2011/9/7

Y1 - 2011/9/7

N2 - The present study reports on the corrosion fatigue behavior of ultrafine-grained (UFG) Niobium 2 wt-% Zirconium (NbZr) alloy in simulated body fluid (SBF). The alloy was processed using multipass equal channel angular processing at room temperature, resulting in a favorable combination of high strength and ductility along with superior biocompatibility and excellent corrosion resistance. Electrochemical measurements revealed stable passive behavior in SBF saline solutions, similar to conventional Ti-6Al-4V alloy. High-cycle fatigue tests showed no alteration in the crack initiation behavior due to the SBF environment, and an absence of pitting and corrosion products. More severe test conditions were obtained in the fatigue crack growth experiments in saline environments. Crack growth rates in UFG NbZr were marginally increased in SBF as compared to laboratory air at a constant test frequency of 20 Hz. Upon a 100 fold decrease in the test frequency, slightly higher crack growth rates were observed only in the near-threshold region. Such excellent corrosion and corrosion fatigue properties of UFG NbZr recommend it as an attractive new material for biomedical implants.

AB - The present study reports on the corrosion fatigue behavior of ultrafine-grained (UFG) Niobium 2 wt-% Zirconium (NbZr) alloy in simulated body fluid (SBF). The alloy was processed using multipass equal channel angular processing at room temperature, resulting in a favorable combination of high strength and ductility along with superior biocompatibility and excellent corrosion resistance. Electrochemical measurements revealed stable passive behavior in SBF saline solutions, similar to conventional Ti-6Al-4V alloy. High-cycle fatigue tests showed no alteration in the crack initiation behavior due to the SBF environment, and an absence of pitting and corrosion products. More severe test conditions were obtained in the fatigue crack growth experiments in saline environments. Crack growth rates in UFG NbZr were marginally increased in SBF as compared to laboratory air at a constant test frequency of 20 Hz. Upon a 100 fold decrease in the test frequency, slightly higher crack growth rates were observed only in the near-threshold region. Such excellent corrosion and corrosion fatigue properties of UFG NbZr recommend it as an attractive new material for biomedical implants.

KW - Corrosion fatigue

KW - ECAP

KW - Implant materials

KW - Niobium alloys

KW - UFG

UR - http://www.scopus.com/inward/record.url?scp=81455131502&partnerID=8YFLogxK

U2 - 10.1016/j.jmbbm.2011.08.023

DO - 10.1016/j.jmbbm.2011.08.023

M3 - Article

C2 - 22100093

AN - SCOPUS:81455131502

VL - 5

SP - 181

EP - 192

JO - Journal of the Mechanical Behavior of Biomedical Materials

JF - Journal of the Mechanical Behavior of Biomedical Materials

SN - 1751-6161

IS - 1

ER -