Fatigue behavior of TiNi foams processed by the magnesium space holder technique

Date

2011-11-01

Author

Nakas, G. Ipek
Dericioğlu, Arcan Fehmi
Bor, Sakir

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

212
views

0
downloads

While the wide range of applications of TiNi alloys makes them highly appealing due to their shape memory and superelasticity properties, the production of TiNi in the porous form further enlarges their application fields. Porous TiNi alloys have been studied extensively for biomedical applications since their elastic modulus is similar to that of bone. Accordingly, TiNi foams have been widely characterized in terms of their various mechanical properties; however, their fatigue properties have not been well studied, even though this is of vital importance in structural applications such as medical implants. In the scope of this study, TiNi foams processed from prealloyed powders by the magnesium space holder technique were mechanically characterized by monotonic and cyclic compression tests. TiNi foams with a porosity range of 49-64 vol.%, which is suitable for bone ingrowth, were determined to have a compressive strength varying in the range 93.27-273.45 MPa. Moreover, the wide range of elastic modulus values obtained (2.93-8.71 GPa) is promising for fulfilling various requirements of different implant applications without causing stress shielding. On the other hand, the endurance limit of TiNi foams was determined to be 0.6 sigma(y), where sigma(y) is the yield strength, independent of the porosity content. Fractography studies on the failed foams after fatigue testing revealed that the failure occurs by the coalescence of micro-cracks initiated from pore walls leading to macro-crack formation aligned at 45 degrees with respect to the loading axis.

Subject Keywords

Mechanics of Materials, Biomaterials, Biomedical Engineering

URI

https://hdl.handle.net/11511/46913

Journal

JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS

DOI

https://doi.org/10.1016/j.jmbbm.2011.06.021

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

Fabrication of functionalized citrus pectin/silk fibroin scaffolds for skin tissue engineering Türkkan, Sibel; Atila, Deniz; Akdağ, Akın; Tezcaner, Ayşen (Wiley, 2018-10-01) In this study, novel porous three-dimensional (3D) scaffolds from silk fibroin (SF) and functionalized (amidated and oxidized) citrus pectin (PEC) were developed for skin tissue engineering applications. Crosslinking was achieved by Schiff's reaction in borax presence as crosslinking coordinating agent and CaCl2 addition. After freeze-drying and methanol treatment, plasma treatment (10 W, 3 min) was applied to remove surface skin layer formed on scaffolds. 3D matrices had high porosity (83%) and interconnec...
Synthesis of calcium carbonate particles for biomedical applications Oral, Çağatay Mert; Ercan, Batur; Department of Metallurgical and Materials Engineering (2020) Calcium carbonate (CaCO3) particles have been widely used in biomedical applications owing to their biocompatibility and biodegradability. In order to effectively utilize CaCO3 particles in biomedical applications, their physical and chemical properties should be systematically controlled. However, this is a challenging task due to the presence of three different anhydrous CaCO3 polymorphs having complex crystallization behavior. In this thesis, CaCO3 particles were synthesized at distinct environments to c...
Delamination of compressively stressed orthotopic functionally graded material coatings under thermal loading YILDIRIM, BORA; Yilmaz, Suphi; Kadıoğlu, Fevzi Suat (ASME International, 2008-09-01) The objective of this study is to investigate a particular type of crack problem in a layered structure consisting of a substrate, a bond coat, and an orthotropic functionally graded material coating. There is an internal crack in the orthotropic coating layer. It is parallel to the coating bond-coat interface and perpendicular to the material gradation of the coating. The position of the crack inside the coating is kept as a variable. Hence, the case of interface crack is also addressed. The top and bottom...
Fabrication and cellular interactions of nanoporous tantalum oxide Uslu, Ece; Garipcan, Bora; Ercan, Batur (Wiley, 2020-10-01) Tantalum possesses remarkable chemical and mechanical properties, and thus it is considered to be one of the next generation implant materials. However, the biological properties of tantalum remain to be improved for its use in tissue engineering applications. To enhance its cellular interactions, implants made of tantalum could be modified to obtain nanofeatured surfaces via the electrochemical anodization process. In this study, anodization parameters were adjusted to obtain a nanoporous surface morpholog...
Microstructure, microhardness, and biocompatibility characteristics of yttrium hydroxyapatite doped with fluoride Toker, S. M.; Tezcaner, Ayşen; Evis, Zafer (Wiley, 2011-02-01) The current study focused on doping of hydroxyapatite (HA) with constant yttrium (Y3+) and varying fluoride (F-) compositions to investigate its microstructure, microhardness, and biocompatibility. HA was synthesized by precipitation method and sintered at 1100 degrees C for 1 h. Y3+ and F- ion dopings resulted in changes in densities. In x-ray diffraction analysis, no secondary phase formation was observed. Lattice parameters decreased upon ion substitutions. Scanning electron microscopy (SEM) results show...

Citation Formats

G. I. Nakas, A. F. Dericioğlu, and S. Bor, “Fatigue behavior of TiNi foams processed by the magnesium space holder technique,” JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS, pp. 2017–2023, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46913.