title: Interfacial characteristics and determination of cohesive and adhesive strength of plasma-coated hydroxyapatite via nanoindentation and microscratch techniques.
abstract: We investigate the chemical composition and mechanical properties of plasma-deposited hydroxyapatite on grit-blasted Ti-6Al-4V coupons as models of typical prosthetic hip implants. Nanoindentation is used to extract the mechanical properties of the hydroxyapatite (HA) coating and to evaluate the behavior of the material as a function of distance from the interface. A microscratch technique was used to determine parameters of cohesive and adhesive failure of the material that are critical in determining the functionality of these biomedical devices. This delamination method has not been studied in detail before and is usually considered to be unsuitable because of the thickness of the HA and the roughness of the substrate. However, through cross-section analysis of the scratch test, we can determine the point at which the HA delaminates from the substrate. It was concluded that spallation occurs locally, and there is no evidence of gross spallation, indicating that the coating is well adhered to the substrate.
authors.affiliation: Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin , Dublin, 2, Ireland.
authors.forename: Colm
authors.initials: C
authors.lastname: McManamon
authors.forename: Johann P
authors.initials: JP
authors.lastname: de Silva
authors.forename: John
authors.initials: J
authors.lastname: Power
authors.forename: Sonia
authors.initials: S
authors.lastname: Ramirez-Garcia
authors.forename: Michael A
authors.initials: MA
authors.lastname: Morris
authors.forename: Graham L W
authors.initials: GL
authors.lastname: Cross
mesh_terms: D000269:Adhesives; D000535:Aluminum / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014639:Vanadium / Q000737:chemistry
chemical_list: D000269:Adhesives; D020099:Coated Materials, Biocompatible; D014639:Vanadium; D017886:Durapatite; D000535:Aluminum; D014025:Titanium