Residual stress in hydroxyapatite coating: nonlinear analysis and high-energy synchrotron measurements

• Published in: IEEE transactions on biomedical engineering Vol. 52; no. 7; pp. 1161 - 1166
• Main Authors: Fogarassy, P., Cofino, B., Millet, P., Lodini, A.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.07.2005; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adsorption; Coated Materials, Biocompatible - analysis; Coated Materials, Biocompatible - chemistry; Coatings; Computer Simulation; Durapatite - analysis; Durapatite - chemistry; Elasticity; Finite element methods; Finite-element analysis; Hydroxyapatite; interface; Lead; Materials Testing; Models, Chemical; Nonlinear Dynamics; Plasma measurements; Prosthetics; Radiation; Residual stress; Residual stresses; Stress measurement; Stress, Mechanical; Surface Properties; synchrotron diffraction; Synchrotron radiation; Synchrotrons; Thermal spraying; Titanium - analysis; Titanium - chemistry; Titanium alloys; X-Ray Diffraction - methods
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2005.847526

The thermal deposition of hydroxyapatite (HA) on titanium alloy substrate (Ti-6Al-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.