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Lifetime prediction of coated implants: study of time and loading dependent local deterioration mechanisms at interfaces and critical degrading effects

English title Lifetime prediction of coated implants: study of time and loading dependent local deterioration mechanisms at interfaces and critical degrading effects
Applicant Pardo Ainhoa
Number 171412
Funding scheme Marie Heim-Voegtlin grants
Research institution EMPA
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Material Sciences
Start/End 01.02.2017 - 31.01.2019
Approved amount 309'539.00
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Keywords (8)

Coated implants; Interfaces; Crevice corrosion; Wear; Deterioration mechanism; Fatigue; Fatigue corrosion; Diamond Like Carbon (DLC)

Lay Summary (German)

Lead
Eine zuverlässige Schätzung der Adhäsionsdauer eines Diamond Like Carbon (DLC) beschichteten Implantats erfordert ein tiefes Verständnis der Fehlermechanismen. Tatsächliche Vorhersagen umfassen nicht die Relevanz langsamer Prozesse an der Schnittstelle, die einen vorzeitigen Bedarf an Operationen verursachen. Die Stabilität und Verschleiß / Ermüdungseigenschaften werden analysiert, indem die ursprüngliche Leistung der Beschichtungen im Körper nachgeahmt wird. Der Rissfortschritt und die Materialauflösung durch Stress, Riss- und Ermüdungskorrosion, passive Oberflächenoxidation und Ermüdung werden bei dynamischen Verschleißtests untersucht.
Lay summary

Der Projektansatz konzentriert sich auf zeitabhängige Effekte auf die wenigen atomaren Zeilen reaktiv geformten Materials an der Grenzfläche, die kritisch an Delaminierungsprozessen beteiligt sind. Ermüdung und Korrosionsermüdung der Grenzfläche werden durch Anpassung und Entwicklung von zwei dynamischen Konfigurationen, die in korrosiven Medien betrieben werden, untersucht: i) Hin- und Herbewegung des Gleitens über modifizierte Oberflächen zur Beschleunigung der Delaminierung, ii) alternierende Grenzflächenbelastung an einer Kante von mechanisch belasteten Grenzflächen. Die Grenzfläche wird chemisch durch Röntgen-Photoelektronenspektroskopie (XPS) analysiert und mit mehreren mit kontrollierten Kontaminantenkonzentrationen getestet. Die Finite-Elemente-Berechnung wird durchgeführt, um ein quantitatives Verständnis der Wechselspannung zu erhalten, die an der Schnittstelle erzeugt wird.

Unsere Arbeit wird maßgeblich mit Informationen über Versagensmechanismen von DLC-gekoppelten biomedizinischen Implantaten beitragen, was für die Lebenszeitvorhersagegenauigkeit und die nachfolgende Verbesserung der Leistungsfähigkeit entscheidend ist.
Direct link to Lay Summary Last update: 16.01.2017

Responsible applicant and co-applicants

Name Institute
Pardo Ainhoa EMPA

Employees

Name Institute
Pardo Ainhoa EMPA

Publications

Publication
o Corrosion fatigue in DLC coated articulating implants: an accelerated methodology to predict realistic interface lifetime
PardoAinhoa, o Corrosion fatigue in DLC coated articulating implants: an accelerated methodology to predict realistic interface lifetime, in Science and Technology of Advanced Materials.

Collaboration

Group / person Country
Types of collaboration
Laboratory of Ion Beam Physics/ETH-Zürich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Laboratory for Mechanical Systems Engineering/EMPA Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Laboratory for Nanoscale Materials Science/EMPA Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Kantonspital Wintherthur Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Laboratory of Mechanics of Materials and Nanostructures/EMPA Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Tribology and Interfacial Chemistry Group/EPFL Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Advanced Power Semiconductory Laboratory/PSI Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Swiss Tribology Technical Meeting 2018 Individual talk Towards a realistic lifetime prediction of DLC-coated articulating implants 16.11.2018 Empa Dpübendorf, Switzerland Pardo Ainhoa;
16th International Conference on Plasma Surface Engineering Poster Synthesis of highly adhesive and hard amorphous carbon films on Silicon and PTFE substrates by dual magnetron sputtering for sensing applications 17.09.2018 Garmisch, Germany Pardo Ainhoa;
The European Corrosion Congress Talk given at a conference Accelerated tests for coating adhesion lifetime estimation in body fluid 09.09.2018 Krakow, Poland Pardo Ainhoa;
European Conference on Nanofilms Talk given at a conference Realistic lifetime estimation of protective DLC coatings for articulating biomedical implants: combined dynamic and corrosion wear test 20.03.2018 University of Cranfield, Cranfield, UK, Great Britain and Northern Ireland Pardo Ainhoa;
Meet the expert-Implants: Materials and Surface Technology for implants Poster Lifetime estimation of coated articulating implants: accelerated testing to address crevice, stress and fatigue corrosion 13.03.2018 FHNW Campus Olten, Switzerland Pardo Ainhoa;
European Conference on Applications of Surface and Interface Analysis Talk given at a conference Analysis of buried interfaces and interlayers 24.09.2017 Montpellier, France Pardo Ainhoa;
28th International Conference on Diamond and Carbon Materials Talk given at a conference Towards realistic lifetime estimation of carbon coated articulated implants 03.09.2017 Göthenburg, Sweden Pardo Ainhoa;
23rd Annual Meeting of the Swiss Society for Biomaterials and Regenerative Medicine: Advances in Antimicrobial Biomaterials Poster Advances in lifetime predictions of DLC coated articulating implants 17.05.2017 Empa-St Gallen, Switzerland Pardo Ainhoa;


Associated projects

Number Title Start Funding scheme
182987 Hard X-ray Photoelectron Spectrometer with environmental processing chamber for depth-resolved chemical-state analysis of functional thin films and their buried interfaces 01.11.2019 R'EQUIP
156085 Predicting deterioration phenomena at coating/implant interfaces in-vivo 01.09.2015 Project funding

Abstract

The goal of the project is to obtain a reliable estimation and understanding of the adhesion lifetime of a coating on a substrate, especially Diamond Like Carbon (DLC) coated implants. The strategy will deal with the stability and wear/fatigue properties of the interfaces in a corrosive media, imitating the original performance of the coatings in the body. The novel approach consists on the study of time dependent effects on the few atomic rows of reactively formed material at the interface, which plays a crucial role in the delamination processes. Actual predictions do not comprise the relevance of slow processes at the interface which cause a premature need of surgeries. Therefore, processes such as crack advancement and material dissolution by stress, crevice and fatigue corrosion, passive surface oxidation and fatigue, will be studied. The project proposes the development and adaptation of two dynamic setups capable of predicting much faster and with more accuracy than actual ones the lifetime of the implants, considering corrosive media at which they are working in the human body. Firstly, fatigue and corrosion fatigue of an interface in physiological media will be investigated by reciprocating sliding of surfaces previously modified to accelerate delamination processes. Secondly, a novel equipment to characterize dynamic sub micrometer stress corrosion cracking and crevice corrosion though microcapillary measurement of mechanically loaded interfaces will be developed, with an alternating interface load at an edge of the DLC film. The interface itself and several substrates will be chemically analyzed by X-ray Photoelectron Spectroscopy (XPS), and afterwards tested by studying different DLC coatings and the contamination effects during the growing process. Finite Elements calculation of interface load and stress intensity at the crack tip for the different equipment and coating systems will be carried out to obtain quantitative understanding of the alternating load generated at the interface.
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