Production of Shape Memory and Biodegradable Fe-Mn-Si-Ti-Mg-Zn-C Alloy Foam for Temporary Implant Applications
Helal Hassoun
Metallurgical and Materials Engineering Department, Istanbul University-Cerrahpasa, 34320, Istanbul, Turkey.
Ilven Mutlu
*
Metallurgical and Materials Engineering Department, Istanbul University-Cerrahpasa, 34320, Istanbul, Turkey.
*Author to whom correspondence should be addressed.
Abstract
In this study, nonmagnetic and bioresorbable iron alloy foam was fabricated for bomedical implant applications. Mn and Si were included in order to obtain shape memory effect. Ti was included in order to enhance biocompatibility. Mg and Zn wre included in order to increase biodegradation rate. C was included in order to prevent ferromagnetic properties. Mg alloys biodegrade too fast with H2 evolution. Zn alloys show biodegradation rates in the middle of Mg and Fe alloys, but the Zn alloys are very brittle. Zn also shows low strength and low plastic deformation. Fe alloys show strength and radio-opaqueness, which is important in the coronary stents. Fe alloy specimens with open porous structure were fabricated by space holder method. Carbamide was used as a space holder. Biodegradation rate was investigated by weight loss measurements. Microstructure was investigated by using optical microscope and scanning electron microscope. Young’s modulus values of the porous Fe-4Mn-4Si-2Ti-5Mg-5Zn-0.5C alloy specimens were deceased from 4.6 GPa to 4.2 GPa with immersion time. Weight change value of the Fe-4Mn-4Si-2Ti-5Mg-5Zn-0.5C alloy was 7.9 % for 21 days immersion period in SBF solution, which is a suitable period for temporary implants. Fe-4Mn-4Si-2Ti-5Mg-5Zn-0.5C alloy does not have a cytotoxic potential on the cells according to neutral red uptake assay. As a result, Fe-4Mn-4Si-2Ti-5Mg-5Zn-0.5C alloy has showed mechanical properties and biodegradation rate suitable for temporary implant material in biomedical applications.
Keywords: Implant, metal foam, biodegradation, Fe alloy, powder metallurgy