Engineering Commons^™

An Investigation On Biocompatibility Of Bio-Absorbable Polymer Coated Magnesium Alloys, Sushma Amruthaluri

FIU Electronic Theses and Dissertations

Advances in biomaterials have enabled medical practitioners to replace diseased body parts or to assist in the healing process. In situations where a permanent biomaterial implant is used for a temporary application, additional surgeries are required to remove these implants once the healing process is complete, which increases medical costs and patient morbidity. Bio-absorbable materials dissolve and are metabolized by the body after the healing process is complete thereby negating additional surgeries for removal of implants.

Magnesium alloys as novel bio-absorbable biomaterials, have attracted great attention recently because of their good mechanical properties, biocompatibility and corrosion rate in physiological environments. …

Electrochemical-Mechanistic Model For Concrete Cover Cracking Due To Corrosion Initiated By Chloride Diffusion, Goli Nossoni, Ronald S. Harichandran

Civil Engineering Faculty Publications

A holistic electrochemical-mechanistic model of the corrosion of steel reinforcing bars inside concrete that accounts for the diffusion of oxygen and moisture into the concrete and rust layers, the densification of rust due to confinement, the flow of rust into the concrete pores, the development of internal pressure due to rust buildup, and cracking of the concrete cover is presented. The relationship between the corrosion current and the pressure buildup due to the corrosion products for different concrete cover thicknesses and concrete quality was calibrated through experiments using an accelerated corrosion test with an applied current. Results from finite-element analysis …

In Vitro Immersion Behavior Of Cold Sprayed Hydroxyapatite/Titanium Composite Coatings, Lin Lu, Xuan Joe Zhou, Pravansu Mohanty

Electrical & Computer Engineering Publications

In previous study, dense and homogenous 20wt% HAP/Ti composite coatings were successfully deposited on Ti substrates by cold gas dynamic spray technique. The results revealed that the phase composition of the HAP in the deposit is identical to that of the precursor powder and the bonding strength of the deposit is comparable/better to that of the plasma sprayed HAP. A relatively higher corrosion current of HAP/Ti composite than that of pure Ti coating in simulated body fluid indicates a good bioactivity for composite coating. In the present study, in vitro immersion test is carried out for various period of time …

Applications Of Scanning Electrochemical Microscopy (Secm) For Local Characterization Of Az31 Surface During Corrosion In A Buffered Media, Sina S. Jamali, Simon E. Moulton, Dennis E. Tallman, Maria Forsyth, Jan Weber, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Different modes of scanning electrochemical mapping (SECM) such as surface generation/tip collection (SG/TC), amperometry, AC-SECM and potentiometry were employed to characterize the active/passive domains, hydrogen gas (H2) evolution and local pH on a corroding surface of AZ31 in simulated biological fluid (SBF). It was found that the main domains of H2 evolution are associated with lower insulating properties of the surface as well as higher local pH. The near surface pH was found to be highly alkaline indicating that, even in a buffered solution such as SBF, the local pH on a corroding AZ31 surface can be significantly different to …

Thermodynamic Considerations Of The Corrosion Of Nickel Ferrite Refractory By Na3alf6-Alf3-Caf2-Al 2o3 Bath, Raymond Longbottom, Sharon Nightingale, Brian Monaghan

Faculty of Engineering and Information Sciences - Papers: Part A

Thermodynamic analysis was carried out to interpret the results of corrosion testing of nickel ferrite samples in cryolite-based baths. The equilibrium between cryolite-based baths and nickel ferrite was considered. Isopleths between cryolite-based baths and nickel ferrite confirmed that for the temperature range of interest (1223-1273 K) there was limited solubility of nickel ferrite in the bath. To better understand the formation of the metal from nickel ferrite, the effect of reducing potentials on nickel ferrite and nickel ferrite-cryolite-based bath systems were considered. The formation of a metal phase was predicted at relatively high pO2. The metal phase was nickel-rich at …