A Model for the Calculation of Mechanical Properties of Hydroxyapatite Coatings on Ti6Al4V Substrate Using Finite Element Methods

Ahmet Pasinli,Mustafa Toparli,Erdal Celik,Osman Culha

doi:10.3390/mca16010136

Ahmet Pasinli, Mustafa Toparli + Show 2 more

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https://doi.org/10.3390/mca16010136

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Abstract

The scope of this study is to find out yield curve on the coating-substrate system of hydroxyapatite (HA) by finite element modeling. With this regard, Hydroxyapatite (HA) coatings were successfully formed on Ti6Al4V substrates by using biomimetic technique. Experimental indentation tests were conducted on Dynamic Ultra-micro Hardness test machine. In finite element modeling (FEM), mechanical properties of coatings were determined by using ABAQUS software package. This numerical study was carried out using an axisymmetric FEM model. To calculate the mechanical properties of coating, the resulting load–unload test data of the samples obtained from the experimental indentation tests were analyzed and curvefitted in Kick’s and Meyer’s law for the loading and the unloading part of the loadunload curve respectively. Then, a set of analytical functions that take the pile-up and sink-in effects into account during instrumented sharp indentation were solved using numerical methods These analytical functions were defined within an identified representative plastic strain, εr, for the Vickers indenter geometry as a strain level that allows for the description of the indentation loading response independent of strain hardening exponent, n.

Highlights

Calcium phosphate base bioceramics have been in use in medicine and dentistry over thirty years
In-situ biomimetic coating method generally is chosen in these applications
The need for simple clinical processes of HA deposition has lead to the development of chemical immersion techniques, in which titanium implants are allowed to soak in a solution containing high concentrations of calcium and phosphate for a specified period of time

Summary

I TRODUCTIO

Calcium phosphate base bioceramics have been in use in medicine and dentistry over thirty years. The need for simple clinical processes of HA deposition has lead to the development of chemical immersion techniques, in which titanium implants are allowed to soak in a solution containing high concentrations of calcium and phosphate for a specified period of time. This method has been shown to elicit film thicknesses of over 15 μm in 5 days, with apatite-substrate adhesion strengths on the order of 11–30 MPa [4]. 1− ν2 and plug into the equation (1) we can get:

A dh s

MATERIALS A D METHODS

A D DISCUSSIO

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