Title

A TRIBO-ELECTROCHEMICAL APPROACH FOR THE CHARACTERIZATION OF ARTIFICIAL IMPLANT BIOMATERIALS

A TRIBO-ELECTROCHEMICAL APPROACH FOR THE CHARACTERIZATION OF ARTIFICIAL IMPLANT BIOMATERIALS

Authorship

More, Nitin S.; Diomidis, Nikitas; Mischler, Stefano; Roy, Manish; Paul, S.N.

DOI

10.5151/5463-5463-17262

Downloads

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Abstract

β Titanium alloys are potential biomaterials for joint prostheses due to their biocompatibility and increased compatibility with the mechanical properties of bone. Knee and hip joints involve a sliding contact between the femoral head and the accetabular cup thus making the metallic components susceptible to tribocorrosion. Micro-motions occur at the fixation between the implant stem and the bone leading to debris and ion release by fretting-corrosion. Ti-29Nb-13Ta-4.6Zr was tested in Hank’s balanced salt solution at open circuit potential and at an applied potential in the passive region at 370C. Reciprocating tribocorrosion tests were carried out against technical grade ultra high molecular weight polyethylene (UHMWPE), while fretting- corrosion tests were carried out against alumina. Under tribocorrosion conditions, the wear of the alloy is insignificant when sliding against polyethylene. Additionally, the tested alloy showed the ability to recover its passive state during sliding. The abrasivity of the alloy depends on the electrochemical conditions in the contact, while the wear of polyethylene proceeds through 3rd body formation and material transfer. Under fretting-corrosion conditions no recovery of passive state was possible due to the increased contact pressure. The wear resistance of the alloy was found to be dependent on the electrochemical conditions in the contact.

 

β Titanium alloys are potential biomaterials for joint prostheses due to their biocompatibility and increased compatibility with the mechanical properties of bone. Knee and hip joints involve a sliding contact between the femoral head and the accetabular cup thus making the metallic components susceptible to tribocorrosion. Micro-motions occur at the fixation between the implant stem and the bone leading to debris and ion release by fretting-corrosion. Ti-29Nb-13Ta-4.6Zr was tested in Hank’s balanced salt solution at open circuit potential and at an applied potential in the passive region at 370C. Reciprocating tribocorrosion tests were carried out against technical grade ultra high molecular weight polyethylene (UHMWPE), while fretting- corrosion tests were carried out against alumina. Under tribocorrosion conditions, the wear of the alloy is insignificant when sliding against polyethylene. Additionally, the tested alloy showed the ability to recover its passive state during sliding. The abrasivity of the alloy depends on the electrochemical conditions in the contact, while the wear of polyethylene proceeds through 3rd body formation and material transfer. Under fretting-corrosion conditions no recovery of passive state was possible due to the increased contact pressure. The wear resistance of the alloy was found to be dependent on the electrochemical conditions in the contact.

Keywords

Tribocorrosion; Fretting-corrosion; Biomaterials; Artificial Implants.

Tribocorrosion; Fretting-corrosion; Biomaterials; Artificial Implants.