Nanomechanical property characterization of femoral head materials

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Orthopedic Implants under long-term physiological loading could produce changes in the surface mechanical properties and possible failure. The knowledge of mechanical properties and improving the wear resistance of these implants is a key step in determining their performance and eventual application. The present work examines the surface and mechanical properties of six femoral head materials using a nanoindenter and atomic force microscope (AFM). The six materials include Cobalt-Chromium-Molybdenum alloy, Oxinium, Tetragonal Zirconia Polycrystal, Stabilized Magnesia, Zirconia Toughened Alumina and Alumina. Nanoindentation was performed to examine the hardness and elastic modulus of all six materials at three different loads. Nanoscratch and Nanowear tests were performed to study the wear behavior at five different contact loads. The AFM has been utilized for studying the surface topography of the tested materials with sub-nanometer spatial resolution. The results show that the Oxinium has the most optimum mechanical properties and wear resistance for use as an orthopedic implant material.