Engineering Commons^™

Corrosion Protective Film Formation On Mg Alloys Az 31 By Exposure To Dilute Selenite Solutions, Zhiyuan Feng, Charles C. Xu, Dadi Zhang, Rudolph Buchheit

Chemical and Materials Engineering Faculty Publications

The study of protective film formation on Mg alloys by exposure to sodium selenite solutions was conducted. Anodic polarization studies, electrochemical impedance spectroscopy studies, morphological analysis, and Energy-dispersive X-ray spectroscopy were performed on AZ31 Mg alloy after coating treatment in different concentrations of sodium selenite. The corrosion resistance was improved by around 5 times compared with control. Improved resistance to localized corrosion was observed in the coatings treated by 5 mM or 10 mM sodium selenite. The protection mechanism was ascribed to the transformation of selenite to insoluble selenium, the formation of insoluble MgSeO₃ hydrate, and polymerization of amorphous …

Limit Equilibrium Method-Based Shear Strength Prediction For Corroded Reinforced Concrete Beam With Inclined Bars, Yafei Ma, Baoyong Lu, Zhongzhao Guo, Lei Wang, Hailong Chen, Jianren Zhang

Mechanical Engineering Faculty Publications

Shear strength is a widely investigated parameter for reinforced concrete structures. The corrosion of reinforcement results in shear strength reduction. Corrosion has become one of the main deterioration factors in reinforced concrete beam. This paper proposes a shear strength model for beams with inclined bars based on a limit equilibrium method. The proposed model can be applied to both corroded and uncorroded reinforced concrete beams. Besides the tensile strength of longitudinal steel bars, the shear capacity provided by the concrete on the top of the diagonal crack, the tensile force of the shear steel at the diagonal crack, the degradation …

Thin Film Concrete Coatings, Bobby W. Meade, Danny Wells, Theodore Hopwood Ii, Sudhir Palle

Kentucky Transportation Center Research Report

KTC researchers obtained eight types of concrete coatings to assess their performance and resistance to chloride penetration. Researchers evaluated eight of the systems in the field and seven in the laboratory. In the field, coatings were applied to a bridge pier that had suffered degradation and chloride contamination. This site will undergo long term monitoring in order to thoroughly evaluate the coating systems. Adhesion of all products in both field and laboratory application was sufficient to provide a durable coating, and ranged from approximately 500 psi to 1,600 psi. Researchers also tested color and gloss changes, which are early indicators …

Magnesium-Titanium Alloys For Biomedical Applications, Ilona Hoffmann

Theses and Dissertations--Chemical and Materials Engineering

Magnesium has been identified as a promising biodegradable implant material because it does not cause systemic toxicity and can reduce stress shielding. However, it corrodes too quickly in the body. Titanium, which is already used ubiquitously for implants, was chosen as the alloying element because of its proven biocompatibility and corrosion resistance in physiological environments. Thus, alloying magnesium with titanium is expected to improve the corrosion resistance of magnesium.

Mg-Ti alloys with a titanium content ranging from 5 to 35 at.-% were successfully synthesized by mechanical alloying. Spark plasma sintering was identified as a processing route to consolidate the alloy …