Wear and surface degradation of commercial ZTA femoral heads under boundary lubrication conditions.

Autor: Marin E; Ceramic Physics Laboratory, Kyoto Institute of Technology, Kyoto, Japan. Electronic address: n14i0002@kit.ac.jp., Rondinella A; Ceramic Physics Laboratory, Kyoto Institute of Technology, Kyoto, Japan., Zhu W; Department of Medical Engineering for Treatment of Bone and Joint Disorders, Osaka University, Osaka, Japan., McEntire BJ; AMEDICA Corporation, 1885 West 2100 South, Salt Lake City, UT 84119, United States., Bal BS; AMEDICA Corporation, 1885 West 2100 South, Salt Lake City, UT 84119, United States., Pezzotti G; Ceramic Physics Laboratory, Kyoto Institute of Technology, Kyoto, Japan. Electronic address: pezzotti@kit.ac.jp.
Jazyk: angličtina
Zdroj: Journal of the mechanical behavior of biomedical materials [J Mech Behav Biomed Mater] 2017 Jan; Vol. 65, pp. 616-626. Date of Electronic Publication: 2016 Sep 28.
DOI: 10.1016/j.jmbbm.2016.09.038
Abstrakt: The effect of frictional sliding on the surface degradation of commercially available zirconia-toughened alumina (ZTA) femoral heads was studied using a pin-on-ball wear tester under three different lubricating conditions: dry, water, and squalene. Water and squalene were employed under boundary lubrication regimes. Despite the unique (non-standard) character of this apparatus, standard loading conditions could be applied, which effectively determined dynamic friction coefficients as basic material properties. Two types of surface degradation were observed: (i) the polymorphic tetragonal-to-monoclinic (t→m) transformation of the zirconia (ZrO 2 ) dispersoids, and (ii) the off-stoichiometry drift caused by oxygen vacancy formation within the alumina matrix. Scanning laser microscopy (SLM), Raman spectroscopy (RS), scanning electron microscopy (SEM), cathodoluminescence (CL), and X-ray photoelectron spectroscopy (XPS) were utilized to evaluate the fractions of transformed zirconia phase and the stoichiometric evolution of the oxygen sub-lattice at the surface of wear-tested ZTA components. Wear tracks on the surface of the femoral heads were only detected under dry conditions. Dry wear also showed the highest frictional forces and the most pronounced formation of oxygen vacancies among the tested conditions. Conversely, equivalent or greater amounts of the t→m transformation were observed with water and squalene lubrication when compared to the dry wear condition.
(Copyright © 2016 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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