Diamond-like carbon coatings with zirconium-containing interlayers for orthopedic implants.
Six types of diamond-like carbon (DLC) coatings with zirconium (Zr)-containing interlayers on titanium alloy (Ti-6Al-4V) were investigated for improving the biotribological performance of orthopedic implants. The coatings consist of three layers: above the substrate a layer stack of 32 alternating Zr and ZrN sublayers (Zr:ZrN), followed by a layer comprised of Zr and DLC (Zr:DLC), and finally a N-doped DLC layer. The Zr:ZrN layer is designed for increasing load carrying capacity and corrosion resistance; the Zr:DLC layer is for gradual transition of stress, thus enhancing layer adhesion; and the N-doped DLC layer is for decreasing friction, squeaking noises and wear. Biotribological experiments were performed in simulated body fluid employing a ball-on-disc contact with a Si3N4ball and a rotational oscillating motion to mimic hip motion in terms of gait angle, dynamic contact pressures, speed and body temperature. The results showed that the Zr:DLC layer has a substantial influence on eliminating delamination of the DLC from the substrates. The DLC/Si3N4pairs significantly reduced friction coefficient, squeaking noise and wear of both the Si3N4balls and the discs compared to those of the Ti-6Al-4V/Si3N4pair after testing for a duration that is equivalent to one year of hip motion in vivo.
Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701, USA.
Dipankar
D
Choudhury
JOANNEUM RESEARCH Forschungsgesellschaft mbH, Institute of Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf, Austria.
Juergen
J
Lackner
Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701, USA.
Robert A
RA
Fleming
Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701, USA.
Josh
J
Goss
Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
Jingyi
J
Chen
Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701, USA. Electronic address: mzou@uark.edu.
Min
M
Zou
D000497:Alloys; D002244:Carbon / Q000737:chemistry*; D003343:Corrosion; D018130:Diamond; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D019736:Prostheses and Implants; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D016474:Weight-Bearing; D015040:Zirconium / Q000737:chemistry*
D000497:Alloys; D002244:Carbon; D018130:Diamond; D015040:Zirconium; D014025:Titanium
N-doped diamond-like carbon; orthopedic implant; squeaking noise; tribocorrosion; wear resistance; zirconium