Metallic biomaterials have been widely used due to their excellent mechanical properties. Cobalt-chromium-molybdenum alloys, in particular are among the safest for the fabrication of orthopedic prostheses. Nevertheless, the liberation of metallic ions as a result of wear has become a problem due to adverse biological reactions. Thus, surface modification through thermochemical treatments and ceramic coatings may be used to improve the tribological properties of the alloy. In this work, a duplex coating obtained from a boriding thermochemical treatment plus an aluminum-chromium oxynitride coating created by physical vapor deposition was synthesized on an ASTM F-75 cobalt alloy. This surface condition was compared with a borided and an untreated ASTM F-75 cobalt alloy. Surfaces were characterized using scanning electron microscopy (SEM) with energy dispersive spectroscopy, X-ray diffraction, and nanoindentation test. The tribological response was studied by means of a ball-on-disc tribometer under dry-sliding conditions tracking the coefficient of friction, volume loss, wear rate, and surface damage by stereoscopy, profilometry, optical 3D measurements, and SEM. Duplex coating increased the wear resistance 7 times relative to the wear resistance of the untreated sample, and 1.5 times relative to the borided sample.
Bibliographical noteFunding Information:
The authors wish to thank to “ Consejo Nacional de Ciencia y Tecnología ” CONACYT for providing a master research fellowship and express their gratitude to CIDET (FIME), CIIIA, COMIMSA and UDEM for allowing to perform each test, and also to “3G Herramientas” (Monterrey, Mexico) for the synthesis of the PVD coatings.
© 2020 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry