Physical Sciences and Mathematics Commons^™

An Approach For Material Model Identification Of A Composite Coating Using Micro-Indentation And Multi-Scale Simulations, Pouya Shojaei, Riccardo Scazzosi, Mohamed Trabia, Brendan O’Toole, Marco Giglio, Xing Zhang, Yiliang Liao, Andrea Manes

Mechanical Engineering Faculty Research

While deposited thin film coatings can help enhance surface characteristics such as hardness and friction, their effective incorporation in product design is restricted by the limited understand-ing of their mechanical behavior. To address this, an approach combining micro-indentation and meso/micro-scale simulations was proposed. In this approach, micro-indentation testing was conducted on both the coating and the substrate. A meso-scale uniaxial compression finite element model was developed to obtain a material model of the coating. This material model was incorporated within an axisymmetric micro-scale model of the coating to simulate the indentation. The proposed approach was applied to a Ti/SiC metal …

Electrochemical Performance Of Moo2-C Composite Coatings, Quan-Yi Li, Qi Yang, Yan-Hong Zhao

Journal of Electrochemistry

The molybdenum dioxide-carbon(MoO₂-C)composite coatings on the surface of Cu foils were prepared by simple knife coating route and followed by sintering in vacuum. The morphology, composition, structure and electrochemical performance of the MoO₂-C composite coatings were investigated. The results demonstrated that the MoO₂-C composite coatings consist of MoO₂ nano-particles with monoclinic crystal structure and amorphous carbon. Some MoO₂ nano-particles with a size range of 5-30nm were loaded on the surface of carbon matrices; while some MoO₂ nano-particles with a size of ~5nm were encapsulated inside. The composite coatings showed porous structure …

Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki

Mechanical Engineering ETDs

Carbon nanotubes (CNTs) are a promising candidate for next generation of electrical wirings and electromagnetic interference (EMI) shielding materials due to their exceptional mechanical and electrical properties. Wires and coatings from ultralong nanotubes that are highly crystalline, well-aligned and densely packed can achieve this goal. High-performance CNT conductors will be relatively lightweight and resistant to harsh conditions and therefore can potentially replace current conductors in many industries including aerospace, automotive, gas and oil.

This thesis investigates a new manufacturing approach, based on conventional solution coating and wire drawing methods, to fabricate high conductivity wires and coatings from ultra-long carbon nanotubes. …

Usage Of Fomblin Y To Improve Water Repellence Of Surface Coatings, Shawn Pj Kirby, Jeffrey Alston, Andrew Guenthner

STAR Program Research Presentations

Fluoro-Decyl POSS (FDP) has shown strong potential as a water repellant surface coating. Additionally, Fomblin is a solvent believed to have the ability to control the crystallization of POSS compounds on surfaces. Controlling the crystallization is key to improving water repelling abilities of surfaces. Thus, dip coating FDP and Fomblin onto surfaces is being investigated for water repulsion, mechanical stability, and deposition feasibility. First, temperature dependence of solubility of Fluoro-Decyl POSS in Fomblin was tested using Dynamic Light Scattering. Relative water repelling abilities of different coatings were determined by measuring contact angle of surfaces with water. Coatings with and without …

Surface Structure And Electrochemical Performance Of Zno Coated Lini1/3Co1/3Mn1/3O2, Chang-Wei Liu, Yu Wang, Yu-Zhong Guo, Lu-Lu Dan, Jian-Hua Wang

Journal of Electrochemistry

The surface of LiNi_1/3Co_1/3Mn_1/3O₂ particles were modified by ZnO. Surface structure and electrochemical properties of the coated materials were investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical tests. The results show that a ZnO coating affects the surface composition of LiNi_1/3Co_1/3Mn_1/3O₂ particles. The surface contents of nickel and manganese increase with the amount of ZnO coating. ZnO can react with LiNi_1/3Co_1/3Mn_1/3O₂ and a complex oxide is formed during the heat-treatment at above 400 ^oC. The …

Re-Healable Coating Based Upon Thermally Responsive Linkages, Dahlia Ningrum Amato

Master's Theses

The goal of this thesis was to design thermally responsive polyol resins that would be compatible with isocyanates. Two approaches were made to reach this goal, the first involved functionalizing soybean oil and the second involved post-polymerization modification of a methacrylate based resin.

A soybean based coating with thermally responsive Diels-Alder linkages has been prepared following an automotive two-component formulation. The resulting coatings displayed the capability to be healed following physical deformation by a thermal stimulus, and such a material has significant potential for end users. Various curing agents were employed, and resulted in variation of scratch resistance and re-healablity. …

Synthesis And Electrochemical Properties Of High-Capacity Cathode Material 0.08lico0.75Al0.25O2-0.92linio2, Ru-Ying Wang, Tian Qiu, Chong Mao, Wen-Sheng Yang

Journal of Electrochemistry

CoAl-LDH or Co(OH)₂ coated spherical Ni(OH)₂ precursors were obtained via a co-precipitation method at a constant pH. The mixtures of the precursors and LiOH.H₂O were annealed at high temperature in O₂ atmosphere, and then the cathode materials of 0.08LiCo_0.75Al_0.25O₂-0.92LiNiO₂, 0.08LiCoO₂-0.92LiNiO₂ and LiNiO₂ were synthesized. Effects of the coating layer were also studied. The results showed that the 0.08LiCo_0.75Al_0.25O₂-0.92LiNiO₂ material possessed the best rate and cycle life performance. The discharging capacities at 0.1C, 0.5C and 3C were …

The Development Of Transparent, Processable, Thermally-Responsive Coatings, Christopher David Roland

Master's Theses

Polymer matrices are commonly used as guest-host systems for organic chromophores for use in non-linear optical materials. The chromophores must be aligned or poled in an electric field in order to impart anisotropy and non-linear activity to the material. This poling process raises several issues, the two largest being the eventual relaxation of the chromophores back into random orientations due to brownian motion, and high molecular weight polymer matrices limiting chromophore mobility during poling. The prevention of this relaxation process is an area of significant interest, especially in applications that require long term coating stability and activity. In this study, …

Corrosion Protection Of Aa 2024-T3 Aluminium Alloys Using 3, 4-Diaminobenzoic Acid Chelated Zirconium-Silane Hybrid Sol-Gels, P.C. Rajath Varma, John Colreavy, John Cassidy, Mohamed Oubaha, Colette Mcdonagh, Brendan Duffy

Articles

Organic-inorganic polymers formed by hydrolysis/condensation reactions of alkoxide precursors, such as organically modified silanes (Ormosils) have found applications as electronic, optical and protective coatings. Such coatings possess important characteristics such as chemical stability, physical strength and scratch resistance. Further performance improvement is achieved through the incorporation of zirconium and titanium based nanoparticles, also formed through the sol-gel process. However due to the inherent difference in the reactivity of the precursors, the hydrolysis of each precursor must be carried out separately before being combined for final condensation. Zirconium precursors are commonly chelated using acetic acid or acetyl acetonate prior to hydrolysis, …

Effect Of Organic Chelates On The Performance Of Hybrid Sol–Gel Coated Aa2024-T3 Aluminium Alloys, Rajath Varma, John Colreavy, John Cassidy, Mohamed Oubaha, Colette Mcdonagh, Brendan Duffy

Articles

Sol–gels are organic–inorganic polymers formed by hydrolysis/condensation reactions of alkoxide precursors, primarily silanes, which have found applications as electronic, optical and protective coatings. These coatings possess important characteristics such as chemical stability, physical strength and scratch resistance. Further performance improvement is achieved through the incorporation of zirconium and titanium based nanoparticles, also formed through the sol–gel process. However due to the inherent difference in the reactivity of the precursors, the hydrolysis of each precursor must be carried out separately before being combined for final condensation. Zirconium precursors are commonly chelated using acetic acids, prior to hydrolysis, to lower the hydrolysis …

Preparation And Performance Of Lifeo_2 Coated Nickel Oxide Cathode For Molten Carbonate Fuel Cells, Chun-Ming Wang, Fei Li, Ke-Ao Hu

Journal of Electrochemistry

A novel cathode for molten carbonate fuel cells was prepared by coating LiFeO 2 over the surface of porous NiO cathode by a simple combustion process. The analytical results of X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated that the LiFeO 2 coating on the surface of NiO particles consisted of nonometer-sized LiFeO 2 grains and sintered tightly with the NiO particles. The LiFeO 2 coating dramatically reduced the contacting area of NiO with the carbonate melts, thus the solubility of NiO in the carbonate melts was decreased. Meanwhile, …

Electrochemical Evaluation On The Porosity Of Electroless Ni-P Alloy Coatings, Hong-Ying Yu, Dong-Bai Sun, Jing-Bing Huang, De-Jun Yang

Journal of Electrochemistry

By investigating the polarization curves of pure Ni P alloy,Ni P alloy coation and carbon steel in nitric acids with different concentrations,the sutable concentration of nitric acid for the evaluation of the porosity of Ni P alloy coatings has been determined and the coatings with different thickness have been evaluated.The results indicated that the nitric acid with 10 wt% concentration is the most suitable solution for the porosity of the coating by using electrochemical method.The polarization curve of Ni P alloy coating in 10% nitric acid can accurately reveal the porosity.With the decrease of the porosity of the coating,the corrosion …