Sergey Yarmolenko

• Ph.D. in Organic Chemistry
• Senior Researcher at North Carolina Agricultural and Technical State University

This research reports the development of 3D carbon nanostructures that can provide unique capabilities for manufacturing carbon nanotube (CNT) electronic components, electrochemical probes, biosensors, and tissue scaffolds. The shaped CNT arrays were grown on patterned catalytic substrate by chemical vapor deposition (CVD) method. The new fabricati...

Previously, we reported 3D Shaped 3D Graphene (3D2G) with controlled structural design. In this work, we introduced cold rolling as a post-processing technique to obtain compressed 3D2G, referred here as C3D2G, and investigated the relationship between its microstructure and properties. The performed comprehensive materials characterization of C3D2...

The disability, mortality and costs due to ionizing radiation (IR)-induced osteoporotic bone fractures are substantial and no effective therapy exists. Ionizing radiation increases cellular oxidative damage, causing an imbalance in bone turnover that is primarily driven via heightened activity of the bone-resorbing osteoclast. We demonstrate that r...

Few studies have investigated the effect of a monosaturated diet high in ω-9 on osteoporosis. We hypothesized that omega-9 (ω-9) protects ovariectomized (OVX) mice from a decline in bone microarchitecture, tissue loss, and mechanical strength, thereby serving as a modifiable dietary intervention against osteoporotic deterioration. Female C57BL/6J m...

Background The primary hot rolling method implemented is differential speed rolling (DSR). The material is rolled and grains are strained, producing fine dynamic recrystallization (DRX) grains that improve material strength and ductility. Objective The material introduced and under investigation in this paper is an Mg-based alloy, Mg5Zn (wt. %), w...

Multilayered Thin films are effective in controlling the rate of corrosion of magnesium alloys used for bio-implants applications. It’s been proven that corrosion of metallic implants can be delayed by depositing multilayered metal-oxide thin films. In this study, Mg/Al 2 O 3 nanolaminates, along with different metal oxides, were deposited using DC...

The influence of diet on the development of osteoporosis is significant and not fully understood. This study investigated the effect of diets of varying lipid profiles and ω-3, ω-6 and ω-9 composition on the structural and mechanical properties of bone. The hypothesis studied was that a diet high in saturated fat would induce osteoporosis and produ...

Magnesium-based alloys can be enhanced through a combination of annealing temperature and holding time prior to plastic deformation such as single-pass differential speed rolling, where the material is strained and produces fine dynamic recrystallization (DRX) grains improving material strength and hardness. The magnesium (Mg)-based alloy under inv...

In the present study, Mg-1.3Zn-0.5Ca (wt.%) magnesium alloy was extruded at 350 ℃ with an extrusion ratio of 9.37, and then the as-extruded alloy was further annealed at 300 ℃, 350 ℃, and 400 ℃ for 0.5 h, 1 h, 2 h, and 4 h to optimize microstructure and mechanical properties. The results show that the bimodal microstructure is the main feature of t...

Earlier, various attempts to develop graphene structures using chemical and nonchemical routes were reported. Being efficient, scalable, and repeatable, 3D printing of graphene-based polymer inks and aerogels seems attractive; however, the produced structures highly rely on a binder or an ice support to stay intact. The presence of a binder or grap...

The present work mainly investigated the effect of extrusion temperatures on the microstructure and mechanical properties of Mg-1.3Zn-0.5Ca (wt.%) alloys. The alloys were subjected to extrusion at 300 °C, 350 °C, and 400 °C with an extrusion ratio of 9.37. The results demonstrated that both the average size and volume fraction of dynamic recrystall...

Non-conventional differential speed and confined hot rolling methods were employed to process two binary magnesium-aluminum-alloys, Mg-xAl (x = 6 and 9 wt%), with conventional rolling being used as a comparative control. The study focused on the effect of the processing methods and parameters on the efficacy of grain refinement and texture evolutio...

Magnesium-6 wt.% aluminum (Mg-6Al) alloy plates with a 6-millimeter thickness were processed from an initial 12-millimeter thickness by differential speed rolling (DSR), with a 0.76-millimeter thickness reduction per pass using a speed ratio of 2, preheating temperature of 315 °C, and roll temperature of 265 °C. The effects of annealing temperature...

Magnesium-based alloys are being used today in various lightweight applications. The mechanical propertiesMechanical Properties of magnesium-based alloys can be enhanced for such applications through a combination of annealing temperature and holding time of the magnesium-based alloy. The magnesium-based alloy under investigation in this study is M...

Selected studies on synthesis, Spark Plasma Sintering, crystal structure and microstructure analysis along with mechanical properties by nanoindentation are presented for ZrB2, HfB2, OsB2, and IrB2 ceramics. ReB2 type hexagonal OsB2 and IrB2 powders were synthesized by mechanochemistry of their precursor elements, while commercial ZrB2 and HfB2 pow...

Understanding the structural and mechanical properties of coral skeletons is important to assess their responses to natural and anthropogenic challenges and to predict the long-term viability of hermatypic corals in a changing ocean. Here, we describe the microstructure of the critically endangered staghorn coral (Acropora cervicornis) skeleton and...

Coral reefs provide habitat for most oceanic life forms, however, they are declining worldwide due to pollution, increased ocean temperature, diseases and other factors. In this paper, structural and mechanical properties of endangered coral (Acropora cervicornis) skeletons cleaned by chemical bleaching and biological processes were studied. The st...

Nanostructured Mg/Zr multilayer films were fabricated by depositing magnesium and zirconium alternately onto a single-crystal Si substrate using magnetron sputtering. The Mg and Zr layers had equal individual layer thickness (h) which was varied from 2.5 to 100 nm. Epitaxial growth and coherent layer interface were identified for the as-deposited m...

Titanium nitride (TiN) thin films are deposited on titanium (Ti) substrates by pulsed laser deposition and radio frequency magnetron sputtering. The main goal of this research is to improve the corrosion resistance and the vibration damping performance of the Ti substrates by surface modification of the substrates with TiN thin film coatings. Elect...

In this study, the Mg-9Al% plates with a total of approximately 50% thickness reduction corresponding to 0.76mm per pass, were obtained by symmetrical and asymmetrical rolling. The effect of different annealing temperature and corresponding holding time on the microstructure and mechanical properties were investigated. Key results showed that in th...

Structure of TiN/CrN Interface in Nanolaminate Coatings with Enhanced Mechanical and Tribological Properties - Volume 25 Supplement - Sergey Yarmolenko, Manohar Konchady, Sudheer Neralla, Alex Kvit, Zhigang Xu, Jag Sankar

Formation of long-period stacking ordered (LPSO) phases can significantly improve mechanical and corrosion properties of Mg-alloys. Typically LPSO phases can be formed by quick solidification of Mg-alloys having at least two alloying elements with atomic radii higher and lower than that of Mg. Stability of LPSO phases greatly depend on amounts and...

MgZnCa and MgZnCa-RE (Rare Earth) alloys were developed for biomedical applications. Small wires of the alloys were successfully fabricated from the small rods prepared by hot-extrusion followed by multiple cold-drawing passes with intermittent annealing. It was demonstrated that addition of small amounts of rare earth (RE) elements could effective...

Objective. We report the study of feasibility to produce the thing bioactive coating from experimental dental cement using pulsed laser deposition (PLD) technique. Methods. The targets for PLD system (disks 30 mm in diameter × 5 mm thick) were sintered from micronized powder of set Alborg White Portland cement (WPC). The parameters for sintering pr...

The micro-alloying effect, mechanical properties, and plastic deformation behavior of extruded Mg-Zr alloy were investigated and characterized as a function of Zr addition, grain size, and texture. The experimental methodology used in this study was design to exploit the hot-extrusion processing parameters (in the terms of extrusion ratios and temp...

Objective. The purpose of this study was to characterize and to evaluate the effect of thermal treatment on properties and bioactivity of experimental dental cement. Methods. Specimens of the dental cement (pellets 13 mm in diameter × 3 mm thick) were prepared by cold pressing of micronized powder of set Alborg White Portland cement. The thermo-gra...

This study describes results from mechanical tests conducted on magnesium single crystals in comparison with polycrystalline magnesium. It was found by impact testing that the magnesium single crystal is highly ductile due to energy absorption by twinning and slip, while the polycrystalline samples fracture easily upon impact. Compressive testing a...

Multiple applications of carbon nanotubes (CNTs) require their assembly into macroscopic materials: films, sheets, and ribbons. Most of these macro-materials are flexible thin structures and need to be cut to micrometer dimensions. Laser cutting has emerged as one of the best pressure-free alternative methods, providing accuracy and uniformity. We...

Composite nanofibers of biopolymers and inorganic materials have been widely explored as tissue engineering scaffolds because of their superior structural, mechanical and biological properties. In this study, magnesium ferrite (Mg-ferrite) based composite nanofibers were synthesized using an electrospinning technique. Mg-ferrite nanoparticles were...

The alignment of different carbon nanotube (CNT) structures has been studied extensively using varying techniques. Most of these techniques however do not present a true three-dimensional (3D) representation of the orientation of the material. In this work, the orientation distribution functions obtained from X-ray pole figures for different CNT st...

This study aims to evaluate the wear resistance of magnesium - ceramics nano-layered thin films using atomic force microscopy technique (AFM). The magnesium - ceramics (alumina and silica) nano-layered thin films were deposited on glass substrate using DC and pulsed DC reactive magnetron sputtering process. The surface roughness and wear properties...

Mg-Zn combinatorial material libraries covering 15–85 at.% Mg were deposited on glass substrates using magnetron sputtering at room temperature. To study the phases present in the Mg-Zn combinatorial libraries the as-deposited sample was annealed at 250 °C for an hour. The composition, phase content and thickness were characterized using energy dis...

This paper discusses the synthesis and characterization of Al2O3/Fe and Al2O3/Ni nanocomposite thin films formed by embedding Fe or Ni nanoparticles into alumina matrix using pulsed laser deposition (PLD), RF and pulsed DC magnetron sputtering techniques. The effect of nanoparticle dispersion and temperature on the phase, structure and mechanical p...

In this study, Mg/SiO2 and MgO/SiO2 multilayer coatings with bilayer thicknesses (Λ) 10, 20, 40, 100, 200 and 1000 nm were deposited on glass substrates using DC and reactive pulsed DC magnetron sputtering processes. The aim of these coatings is to control the initial degradation and provide mechanical strength to magnesium implant during handling...

In recent years, magnesium (Mg) and its alloy are being studied for their potential use in orthopedic implants with the novel ability to biodegrade after the implant serves its therapeutic function. Pure Mg, by itself, would not be suitable for use in a load-bearing implant application, due to its high corrosion rate and poor tribological propertie...

Magnesium has attracted a lot of attention over the last few decades due to its light weight and potential use as biomaterial. However, the poor corrosion resistance of magnesium restricts its practical use for application where exposure to aggressive aqueous media is unavoidable. This paper describes the growth, characterization and corrosion anal...

A biomedical implant is formed from magnesium (Mg) single crystal. The biomedical implant may be biodegradable. The biomedical implant may be post treated to control the mechanical properties and/or corrosion rate thereof said Mg single crystal without changing the chemical composition thereof. A method of making a Mg single crystal for biomedical...

Free-standing thin CNT sheets are challenged with handling and controlling for device fabrication and further transportation problem. In this paper, we report on the inverse-ordered fabrication method from thick carbon nanotube (CNT) sheets to thin free-standing CNT sheets. As proof of the concept, thin CNT sheets for supercapacitor were fabricated...

We have studied semiconductor to metal transition (SMT) characteristics of VO2(011) thin films integrated epitaxially with Si(100) through NiO{001}/MgO{001}/TiN{001} buffer layers and correlated with the details of epitaxy and nature of residual stresses and strains across the VO2/NiO interface. Thin film epitaxy at both room and elevated temperatu...

The mechanical behavior of a lanthanum doped Mg alloy, AZXE7111, (Mg–7Al–1Zn–1Ca–1La, all in wt%) extruded at different temperatures has been investigated under both quasi-static (strain rate ~1×10−3 s−1) and dynamic (strain rate ~4×103 s−1) compressive loading. Comparison has been made against the experimental results of two conventional Mg alloys...

Nanotubes are a unique class of materials because their properties depend not only on their composition but also on their geometry. The diameter, number of walls, length, chirality, van der Waals forces, and quality all affect the properties and performance of nanotubes. This dependence on geometry is what makes scaling-up nanotubes to form bulk ma...

Magnesium and its alloys have been found to potential candidates for biodegradable implant applications. However, magnesium and its alloys are broadly known to have poor tribological properties, but detailed specifics on wear performance are scarce. This research investigates the tribological characteristics on Mg-Zn-Ca-RE alloys and pure magnesium...

Magnesium has attracted a lot of attention over the last few decades, due to its light weight and potential use as biomaterial. However, the poor corrosion resistance of magnesium restricts its practical use for application where exposure to aggressive aqueous media is unavoidable. This paper describes the growth, characterization and corrosion ana...

Atomic force microscopy (AFM) is powerful technique to study surface properties and processes in the μm-and nmrange. In-situ liquid AFM measurements were conducted to evaluate the surface degradation of two biocompatible metals: Ti as the most bio-inert (bio-stable) and Mg as the promising biodegradable metal. The pure Mg and Ti thin films were dep...

INTRODUCTION: Combinatorial technique has drawn attention as a new efficient method for searching and screening new materials [1]. Using combinatorial approach, processing time could be shortened dramatically over the conventional approach. In the present study, the benefit of combinatorial technique in screening the corrosion properties of binary...

We have used magnetron sputtering to deposit magnesium and titanium layers alternately onto a single-crystal silicon substrate with equal individual layer thickness (h, from 2.5 to 200 nm) to form multilayers. We have investigated the mechanical behavior of the multilayers and its dependence on h. Transmission electron microscopy and X-ray diffract...

As the need for smaller data storage devices in the market continues to grow, the study of new combinations of self-assembled magnetic nanoparticles/films is greatly needed. In this research, Fe50-Ni50 films were synthesized using a Pulsed Laser Deposition technique. The films were analyzed using scanning electron microscopy (SEM), atomic force mic...

Nanostructured magnesium coatings have the potential of enhancing the integration of implant to bone tissues due to their ability to regulate the functions of integrin, which modulates cell proliferation and differentiation. However, they are soft, ductile and have low wear resistance. These limitations prevent the practical use of Mg coatings for...

The electrochemical, transport and thermomechanical properties of perovskite-type (La-1 (-) Sr-x(x))(1 - y)Mn0.5Ti0.5O3 (-) (delta) (x = 0.15-0.75; y = 0-0.05), (La0.75 - xSr0.25 + x)(0.95)Mn0.5Cr0.5 - xTixO3 - delta (x = 00.5), (La0.75Sr0.25)(0.95)Cr1 - xFexO3 (- delta) (x = 0.3-0.4), SrNb1 - xMnxO3 - delta (x = 0.50.8) and (La0.9Sr0.1)(0.95)Cr0.8...

In recent times, magnesium alloys have emerged as a possible biodegradable implant material. Plasma electrolytic oxidation (PEO) has been used in the past as a useful surface treatment technique to improve wear resistance and corrosion resistance of magnesium alloys by forming protective coatings. This study focuses on the effect of electrolyte sol...

Medical change is coming. Robots and tiny machines built using nanoscale materials are going to fundamentally change engineering at the microscale and medicine will be the first area to benefit. In tiny machine design, copper and iron are replaced with carbon nanotube superfiber wire and magnetic nanocomposite materials. Because of the small size o...

In order to enhance the phase stability of dispersions of magnetic nanoparticles (NPs) in a polymorphic liquid crystal, new ligands have been designed consisting of a terphenyl-based liquid crystalline core. The most stable dispersions were obtained with 7 nm super-paramagnetic Fe3O4 NPs decorated with the new ligands in place of 10 nm ferromagneti...

Magnesium and its alloys are great candidates for uses in orthopedic implant applications due to their biocompatibility, mechanical properties and degradability. However, they are susceptible to accelerated degradation rates due to micro galvanic corrosion, which leads to unpredictable corrosion behavior. The poor corrosion resistance limitation re...

Combination of unique properties of inorganic nanoparticles (NPs) with anisotropic properties of liquid crystals is extremely promising for various applications, see, e.g. [1-3] but the problem of stability of the liquid crystal colloids with time has yet to be solved. The most robust colloids in LC known to date were obtained using the LC-like sur...

Quantification of apoptotic tissues during inflammatory processes induced by biomaterials is challenging in vivo. Here we present a non-invasive method using a fluorescence imaging system which facilitates intermittent snap shots of the current state of local apoptotic tissue. For this purpose, apoptotic cells around two different subcutaneously im...

This paper focus on microstructure and measurement of indentation properties of veins of NC dragonfly wings. The wings were sliced into different locations on the wing and sandwiched between two glass slides using M Bond 610 and cured for 24 hrs. The edge of the sandwiched wing structure has polished and the required surface finish was achieved. Th...

It is known that theoretical considerations of fracture under loading by a spherical indenter are based on the concept of pre-existing cracks. However, nucleation and growth of the critical crack could occur during indentation, as happens during microcracking. The goal of the presented research is to develop a new concept of fracture under spherica...

Bulk nanostructured metallic alloys as well as coatings are being research closely for biomedical applications, especially for implants. Corrosion behavior is of particular interest, given the aggressive environment of body fluids that these metals experience. While weight loss measurement and electrochemical analysis are the two commonly used tech...

Scandia-doped zirconia is a very promising material for solid oxide fuel cells due to its high oxygen conductivity in the 700-850°C temperature range. 10 mol% Sc2O3 - 1 mol% CeO2 - ZrO2 ceramics were sintered at temperatures 1100-1600°C using different heating rates and dwell times. Ceramics sintered at temperatures higher 1300°C were found to exis...

We have investigated the effect of chamber pressure and atmosphere on the microstructure and nanomechanical properties of amorphous diamondlike carbon (DLC) thin films prepared by pulsed laser deposition. The amorphous carbon films were deposited in various atmospheres such as nitrogen and argon at different pressures. We used Raman spectroscopy an...

The internal compressive stress as large as 10 GPa has been the major stumbling block for preparation of relatively thick superhard tetrahedral amorphous carbon (Ta-C) films. We have successfully deposited Ta-C films as thick as 1000 nm by mechanical doping to reduce and alleviate the level of internal compressive stresses. In this paper, we report...

Pure diamondlike carbon thin films largely bonded by four-fold coordination suffer from a large internal compressive stress that gives rise to a serious adhesion problem. In this work, functionally gradient (FG) diamondlike carbon thin coatings were prepared by pulsed laser deposition in a high vacuum chamber as an alternative approach to address t...

We have prepared pure diamondlike carbon films and Cu doped diamondlike carbon films through pulsed laser deposition. The Cu concentration does not exceed 3.0 atomic percent. Electrical conduction studies were carried out on the films to understand the electrical transport mechanism. It was found that both pure DLC and Cu doped DLC are of p-type co...

Pure diamondlike carbon thin films largely bonded by four-fold coordination suffer from a large internal compressive stress that gives rise to a serious adhesion problem. In this work, functionally gradient (FG) diamondlike carbon thin coatings were prepared by pulsed laser deposition in a high vacuum chamber as an alternative approach to address t...

An one-pot procedure was developed for the synthesis of mesoporous silica containing bimetallic PdCo using Pd(NO3)2 and CoCl2, and cetyl trimethyl ammonium bromide (CTAB) as the templating agent, and tetramethoxy silane (TMOS) as the precursor. The materials were characterized using high resolution scanning transmission electron microscopy (HRSTEM)...

Pulsed laser deposition (PLD) technique was used to grow alumina (Al 2O3) thin films on (100) silicon substrate under different deposition conditions. The relationship between Al2O3 thin film thickness, hardness, elastic modulus, surface morphology and PLD parameters such as laser energy and substrate temperature was investigated. The Film thicknes...

The tensile strengths of Nextel™ 720 fibers as well as tows and minicomposites made of these fibers were measured to study the effects of monazite coating at room temperature (RT) and 1200°C (HT). Tests were conducted on as-received materials (called unsoaked) as well as materials that had been thermally soaked at HT for 100 hours. Weibull analysis...

Liquid fuel combustion chemical vapor deposition technique was successfully used for YSZ thin film processing. The nucleation rates were obtained for the samples processed at different temperatures and total-metal-concentrations in the liquid fuel. An optimum substrate temperature was found for the highest nucleation rate. The nucleation rate was i...

Individual nanotubes made of carbon, boron nitride, iron, silicon, or other materials have properties such as high strength, toughness, electrical and thermal conductivity, and light weight that cannot be matched by conventional materials. Nanotubes also change their properties in response to external fields and change one type of energy into anoth...

Individual nanotubes made of carbon, boron nitride, iron, silicon, or other materials have properties such as high strength, toughness, electrical and thermal conductivity, and light weight that cannot be matched by conventional materials. Nanotubes also change their properties in response to external fields and change one type of energy into anoth...

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IntroductionExperimentalResults and DiscussionConclusions Acknowledgments

A biosensor is an electronic device that measures biologically important parameters. An example is a sensor that measures the chemicals and materials released during corrosion of a biodegradable magnesium implant that impact surrounding cells, tissues and organs. A responsive biosensor is a biosensor that responds to its own measurements. An exampl...

Magnesium (Mg) is a biodegradable metal that has significant potential advantages as an implant material. In this paper, corrosion and cell culture experiments were performed to evaluate the biocompatibility of Mg. The corrosion current and potential of a Mg disk were measured in different physiological solutions including deionized (DI) water, pho...

The phase composition and sintering behavior of two commercially available 10 mol % Sc2O3-1 mol % CeO2-ZrO2 ceramics produced by Daiichi Kigenso Kagaku Kogyo (DKKK) and Praxair have been studied. DKKK powders have been manufactured using a wet coprecipitation chemical route, and Praxair powders have been produced by spray pyrolysis. The morphology...

In the present study, multilayer TiN/CrN coatings at different bilayer thicknesses have been deposited on silicon (100) and 316 stainless steel substrates using reactive DC magnetron sputtering technique. Nanoindentation, nanoscratch and ball-on-disk tribometer tests were used to characterize the films. Nanoindentation measurements showed enhanceme...

This chapter is an overview of potential applications of carbon nanotube smart materials in biology and medicine. Carbon nanotube arrays are forests of aligned nanotubes prepared on a substrate. The nanotubes have multifunctional properties that include high strength, sensing, actuation, and electronic properties. Several prototype smart material d...

A study of hot pressed B4C-based laminates, after rolling and without rolling, has been performed to elucidate the existence of fracture resistance/crack length anisotropy induced by this processing technique. While the crack lengths/fracture resistance was affected significantly by the presence of the residual stresses in B4C/B4C–ZrB2 laminates, n...

Responsive nanomaterials are being developed through interdisciplinary research to improve and evaluate the performance of engineering assets. An overview of the work is given here. Nanomaterials are defined as bulk materials that have nanoparticle components. Responsive materials art defined as having an intrinsic ability to sense their condition...

Bimetallic nanoparticles of Pd-Co / Pd-Ni in MCM type mesoporous silica have been synthesized by hydro-thermal procedure using Pd(NO3)2, CoCl2, Ni(NO3)2, cetyl trimethyl ammonium bromide (CTAB), tetramethoxysilane (TMOS), ammonia and water. These materials have been characterized using XRD, TEM, FT-IR, and BET techniques. The metal oxides in the me...

Both static and fatigue behavior of sintered silicon nitride was studied in flexure at room and elevated temperatures to determine the effect of temperature and cyclic loading on mechanical properties. An easy and cost effective four-point bending was used during the experimental investigation. It was found from quasistatic flexural tests that both...

Interfacial properties of boron nitride fiber coatings are studied in melt infiltrated Hi–Nicalon/BN(CVI)/SiC composites subjected to room temperature cyclic fatigue loading and long term annealing to 1000–1200°C in air. Interfacial shear strength was determined from single fiber push–out tests. Hi–Nicalon fibers with diameters of 13–14.5 μum were...

Being inherently oxidation resistant, oxide\oxide CMCs are attractive for use in advanced turbines and other structural components operating under extreme environments. A hybrid system (fiber coated oxide\oxide CMC) was selected by the Air Force Materials Laboratory to retain superior material properties at high temperature. Various testing techniq...

The melt infiltration (MI) process is of considerable interest to the ceramics community primarily due to its low cost and near net shape capabilities. This paper presents the results to date of a study of the effect of high temperature on the dynamic properties of SiC/SiC woven ceramic composites manufactured by the MI process. Materials having 5-...

The tensile strengths of Nextel™ 720 fibers were measured at room temperature (RT) and 1200°C (HT) to study the effects of monazite (LaPO4) coating. Tests were conducted on asreceived (unsoaked) materials as well as materials that had been thermally soaked at HT for 100 hours. There is close agreement between the Weibull modulus obtained from the s...

Materials with nanoscale features have new or improved properties compared to bulk materials. These properties depend on the composition, size, and shape of the material, and include high specific strength and modulus, low melting point, high electrical and thermal conductivity, a large surface area to volume ratio, nearly defect-free structure, ma...

There is a wide spread interest in metal-ceramic nanocomposites due to their enhanced mechanical and magnetic properties when the size of metal particles is reduced to nano-scale. This paper presents results from our study of thin film ceramic-metal nanocomposites created by embedding nano-sized Ni metal particles in amorphous alumina matrix using...

Yttria fully stabilized zirconia (YSZ) thin films have been used as an electrolyte in solid oxide fuel cells. The microstructural characteristics of the thin films has played an important role in controlling efficiency and reliability of the fuel cell. Experimental studies have shown that both the grain size and the film texture highly depends on v...

The tensile strengths of fiber tows and minicomposites based on Nextel ™720 fiber were investigated at room temperature (RT) and at 1200°C (HT). Uncoated and monazite coated fibers were used, and the minicomposites were made with an alumina matrix. As-received (‘unsoaked’) and thermally soaked tows and minicomposites were used. It was found that un...