title: Residual stress in hydroxyapatite coating: nonlinear analysis and high-energy synchrotron measurements.
abstract: The thermal deposition of hydroxyapatite (HA) on titanium alloy substrate (Ti-6A1-4V) leads to a structure that has very good osseointegration properties. However, clinical failures have been occasionally reported at the interface between substrate and coating. Lifetime is the main parameter in such prostheses; therefore, in order to improve their quality, it is necessary to evaluate the level of stresses near the interface. The high-energy synchrotron radiation combines the advantages of a bulk analysis and reduced volume of the gauge. The objective of our study was to calculate the residual stress using a nonlinear finite-element model and to measure residual stress level near the interface, in the hydroxyapatite coating and in titanium alloy substrate with a nondestructive and high-resolution experiment. The high-energy synchrotron radiation of the BM16 beam-line at ESRF (Grenoble-France) was used with a resolution of down to 10 micrometers. The experimental measurements validate the results found by means of nonlinear finite-element analysis of the plasma spraying induced stress.
authors.affiliation: LACM, Université de Reims Champagne-Ardenne, Reims 51687, France. paul.fogarassy@univ-reims.fr
authors.forename: Paul
authors.initials: P
authors.lastname: Fogarassy
authors.forename: Bruno
authors.initials: B
authors.lastname: Cofino
authors.forename: Pierre
authors.initials: P
authors.lastname: Millet
authors.forename: Alain
authors.initials: A
authors.lastname: Lodini
mesh_terms: D000327:Adsorption; D000497:Alloys; D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry*; D003198:Computer Simulation; D017886:Durapatite / Q000032:analysis / Q000737:chemistry*; D004548:Elasticity; D008422:Materials Testing; D008956:Models, Chemical; D017711:Nonlinear Dynamics; D013314:Stress, Mechanical; D013499:Surface Properties; D017356:Synchrotrons; D014025:Titanium / Q000032:analysis / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D000497:Alloys; D020099:Coated Materials, Biocompatible; C031462:titanium alloy (TiAl6V4); D017886:Durapatite; D014025:Titanium