Other Materials Science and Engineering Commons^™

Application Of Fly-Ash Composite In Plasma Surface Engineering, Ajit Behera

Ajit Behera

Fly-ash produced from iron & steel industries contains rich amount of metal oxides which gives a tremendous potential as a coating material on structural components. This demand leads to develop and characterize different type of fly ash composite coatings by using plasma spray technique. Plasma spray technology has the advantage of being able to process various low-grade ore minerals to obtain value-added products and also to deposit metals, ceramics and a combination of these, generating approximately homogeneous coatings with the desired microstructure. In the present investigation, coatings are developed on copper substrates using fly-ash+ quartz+ illmenite composite (in a weight …

Coating Material Interaction On Metal Substrate By Application Of Plasma Spraying, Ajit Behera

Ajit Behera

In this paper, Fly-ash+quartz+illmenite with weight percentage ratio: 60:20:20, is deposited on mild steel and copper substrates by atmospheric plasma spraying at various operating power level ranging from 11 to 21 kW. The properties of the coating depend on the interaction of coating powder with plasma, operating condition and the process parameters. The coating quality and behavior depends on Coating surface & interface morphology are studied with Scanning Electron Microscope. For Mild Steel the adhesion strength has varied from 3.5MPa to 6.56MPa and for Mild steel a maximum of 6.56MPa at the power level of 21 kW. In plasma spraying, …

Understanding Size Effects In Small Scale Deformation: A Statistical Perspective, Sudharshan Phani Pardhasaradhi

Doctoral Dissertations

Recent experimental observations of micro-compression / tension tests indicate that as the size of test specimen decreases the yield strength increases. This raises a fundamental question: Why is smaller stronger? Is there a fundamental relationship between the size of a specimen and its intrinsic strength? This simple question pushes the limit of the current understanding of the physical mechanisms underlying material deformation, especially at small scales. In order to explain the experimental observations of the strength of small specimens containing a limited number of dislocations, a simple statistical model is developed. Two different types of randomness are introduced, viz., randomness …

Structure And Dynamics Of High Temperature Superconductors, Jennifer Lynn Niedziela

Doctoral Dissertations

High temperature superconductivity in iron based compounds has presented a series of complex problems to condensed matter physics since being discovered in 2008. The stalwart basis of condensed matter physics is the “strength in numbers" aspect of crystalline periodicity. Perfect crystalline periodicity has made possible the reduction of the questions of structural and electronic properties to single dimensions, increasing the tractability of these problems. Nevertheless, modern complex materials stretch these assumptions to their limits, and it is at this point where our work starts. Using neutron and x-ray scattering, we have conducted a series of studies on the structural disorder …

Application Of Neural Network Analysis To Correlate The Properties Of Plasma Spray Coating, Ajit Behera

Ajit Behera

Thermal spray coatings are more often being demanding process at the recent stages of industrial design processes to become fundamental element of the engineering system. The aim of the present paper is to develop a model-based estimation and control for regulating the coating adhesion strength, by using neural network. This proposed model permits cost reduction by the possibility of adjusting the parameter of the process for each of the desired properties, which can directly act as a quality control process. By this artificial neural network (ANN) technique, the possibility of adhesion strength of the mixture of flyash, quartz and illmenite …

Least Square Support Vector Machine Alternative To Artificial Neural Network For Prediction Of Surface Roughness And Porosity Of Plasma Sprayed Copper Substrates, Ajit Behera

Ajit Behera

Plasma spraying technique has become a subject of intense research in many industrial structural/functional applications because its peculiarity surface properties. This investigation explains about plasma sprayed copper surface property. Here industrial waste and low grade ore (i.e. Flay-ash+ quartz+ illmenite), used as deposit material which is to be coated on copper substrates. In many applications, it is found that for structural modification, surface roughness & porosity parameters are very important. To decrease both surface roughness and coating porosity by optimizing other necessary properties, different soft computing methods like Artificial Neural Network (ANN) and Least Square support vector machine techniques used. …

Lignin Yield Maximization Of Lignocellulosic Biomass By Taguchi Robust Product Design Using Organosolv Fractionation, Anton Friedrich Astner

Masters Theses

Lignin, a byproduct of the organosolv pretreatment process using lignocellulosic biomass from switchgrass (Panicum virgatum) and tulip poplar (Liriodendron tulipifera) is currently being explored for its potential use in the production of value-added chemicals and biobased polymers. Pretreatment is one of the most expensive processing steps in cellulosic biomass conversion. Optimization of the process is one of the major goals of the biomass-toethanol conversion process. Taguchi Robust Product Design (TRPD) provides an effective engineering experimental design method for optimizing a system and designing products that are robust to process variations. Given the results of several preliminary …

Wolfpack Gear Inc. Composite Frame Firefighter Backpack, Gabriel Mountjoy, Blair Ridings, Carl Drummond Buchenroth

Mechanical Engineering

No abstract provided.

A Novel Material Used In Automotive Industry: Compacted Graphite Iron, Ajit Behera

Ajit Behera

In recent decades, materials have been a key to increase the performance of automotive parts which leads to development of new materials. The main objective is to achieve increase in quantity and quality of automotive parts produced with optimum performance during their life cycle. Cast iron has remained a competitive material due, in part, to its low production cost. In fact, among the cast iron group, one of the alternatives is lightweight alloys, that is, compacted graphite iron (CGI). Nowadays, it is accepted that CGI can effectively reduce the total weight of an automobile by virtue of its high strength- …

Magnetic And Elastic Properties Of Magnetostrictive Tb6fe1-Xcoxbi2, Michael Richard Koehler

Doctoral Dissertations

The Tb6[6 sub]Fe1-x[1-x sub]Cox[x sub]Bi2[2 sub] (x = 0, 0.125, 0.25, and 0.375) family of compounds has been synthesized and investigated for magnetostrictive behavior using capacitance dilatometry. These measurements have been complemented by measurements of the elastic moduli using Resonant Ultrasound Spectroscopy (RUS), magnetization measurements (with a vibrating sample magnetometer (VSM)), as well as powder X-ray diffraction (XRD) and powder neutron diffraction measurements and heat capacity measurements.

Each of the compounds studied shows little magnetostriction at the Curie temperature but shows pronounced amounts of magnetostriction at temperatures below 100 K. Magnetostriction values of up to ~980 ppm have been discovered …

Sound Absorption Properties Of Functionally Graded Polyurethane Foams, Olivier Doutres Ph.D., Noureddine Atalla Pr.

Olivier Doutres Ph.D.

Noise control over a wide frequency band is an increasingly important design criterion in the building and transport industries. Examples of well known broadband passive concepts for optimal sound absorption are multi-layering with graded properties across the thickness and optimization of the material shape (e.g., wedges). However, for typical applications, the material thickness is limited and shaping or use of different material costly. Thus, there is growing interest for developing acoustical materials having microstructure properties gradient at the micro- or meso-scale; also known as Functionally Graded Materials (FGM). Even if sophisticated models are available to predict the acoustic behavior of …

Classification Of Biomaterials Used In Medicine, Ajit Behera

Ajit Behera

In this decade many researches are potentially going forward by using biomaterials in the medical field. Biomaterials can used in living creature body, taking in account of there biocompatibility. This paper describes about classification of different biomaterials which are used in medical industries. Advances in surgical technique and instruments have permitted materials to be used in ways that were not possible previously. Bio-material can partially/totally replaces one or more part of the body. Before using biomaterials, it should in mind that, which categories they are belongs and main focuses are on biocompatibility, bioinert, bioactive/surface reactive, biodegradable, sterilizability, adequate mechanical and …

Comparative Study Of Cryo -Treated Steel, Ajit Behera

Ajit Behera

— It is well known that most important problems faced by many industrial machine parts are the wear and tear which increases the cost of production and wasted time for the replacement process. Now-a-days cryogenic treatment would be regarded as one of the most important processes in the field of industries, and it is the ultra modern type of processing to make the metals more resistant to wear and more durable. Cryogenic treatment is an additional process to conventional heat treatment process. It involves freezing of materials at cryogenic temperatures to enhance the physical and mechanical properties of materials. This …

Atomistic Simulations Of Defect Nucleation And Intralayer Fracture In Molybdenum Disulphide During Nanoindentation, James A. Stewart

Graduate Theses and Dissertations

Molybdenum disulphide (MoS2) is a layered, hexagonal crystal that has a very low coefficient of friction. Due to this low coefficient of friction, MoS2 has become a well-known solid lubricant and liquid lubricant additive. As such, nanoparticles of MoS2 have been proposed as an additive to traditional liquid lubricants to provide frictional properties that are sensitive to different temperature and pressure regimes. However, to properly design these MoS2 nanoparticles to be sensitive to different temperature and pressure regimes, it is necessary to understand the mechanical response of crystalline MoS2 under mechanical loading. Specifically, the fundamental mechanism associated with the nucleation …

Magnetic Properties Study Of The Mn-Al System With Additions Of B Or C And Mechanical Milling Techniques, Timothy E. Prost

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Recently a shift in the focus of permanent magnetic research has moved from Rare Earth (RE)-based alloys to those made from more readily available elements. Because of their relatively large magnetocrystalline anisotropy, L1₀ compounds have the potential for use as permanent magnet materials. One particular alloy that is readily available and inexpensive is near equi-atomic manganese and aluminum (Mn₅₀-Al₅₀). First characterized in 1958, it did not receive much attention until more recently when RE supply chain issues made the alloy more attractive for commercial and research applications. The ferromagnetic (FM) τ-phase (L1₀) is …

Pretreatment And Pyrolysis Of Rayon-Based Precursor For Carbon Fibers, Kokouvi Akato

Masters Theses

In this work, two rayon fibers were investigated as carbon fiber precursors. A detailed consideration has been applied to a domestically produced cellulose fiber to carbon fiber (CF) transition. This transition of precursor to carbon fiber can be subdivided into two stages: pyrolysis (thermal decomposition) of cellulose in air and high temperature treatment in an inert atmosphere. The specific objectives were to investigate the stabilization stage of the produced rayon with respect to changes taking place during thermal decomposition, and to evaluate the effects on the properties of the carbonized fiber. Changes taking place during the conversion process of the …

Characteristic Study On Ni50mn45sn5 By Dsc & X-Ray Analysis, Ajit Behera

Ajit Behera

The Martensitic Transformation in Ferromagnetic shape memory alloys (FSMAs) can be triggered not only by changes in temperature and stress as that of paramagnetic conventional shape memory alloys, but also by changes in the applied magnetic field. It is well known that ferromagnetic shape memory alloy has diversified utilization, but not satisfactorily use, mainly because of high cost of processing and high cost of alloying elements. Among all Heusler alloy, Ni-Mn-Sn alloy have potential properties and exhibits lower cost. In this experiment Ni50Mn45Sn5 alloys characterize by using differential scanning calorimetric (DSC), optical microscope and X-Ray diffraction technique. The alloy undergoes …

Phase Field Crystal Approach To The Solidification Of Ferromagnetic Materials, Niloufar Faghihi

Electronic Thesis and Dissertation Repository

The dependence of the magnetic hardness on the microstructure of magnetic solids is investigated, using a field theoretical approach, called the Magnetic Phase Field Crystal model. We constructed the free energy by extending the Phase Field Crystal (PFC) formalism and including terms to incorporate the ferromagnetic phase transition and the anisotropic magneto-elastic effects, i.e., the magnetostriction effect. Using this model we performed both analytical calculations and numerical simulations to study the coupling between the magnetic and elastic properties in ferromagnetic solids. By analytically minimizing the free energy, we calculated the equilibrium phases of the system to be liquid, non-magnetic …

Novel Platform Development Using An Assembly Of Carbon Nanotube, Nanogold And Immobilized Rna Capture Element Towards Rapid, Selective Sensing Of Bacteria, Elizabeth I. Maurer, Kristen K. Comfort, Saber M. Hussain, John J. Schlager, Sharmila M. Mukhopadhyay

Chemical and Materials Engineering Faculty Publications

This study examines the creation of a nano-featured biosensor platform designed for the rapid and selective detection of the bacterium Escherichia coli. The foundation of this sensor is carbon nanotubes decorated with gold nanoparticles that are modified with a specific, surface adherent ribonucleic acid (RNA) sequence element. The multi-step sensor assembly was accomplished by growing carbon nanotubes on a graphite substrate, the direct synthesis of gold nanoparticles on the nanotube surface, and the attachment of thiolated RNA to the bound nanoparticles.

The application of the compounded nanomaterials for sensor development has the distinct advantage of retaining the electrical behavior …

Biaxial & Twist Testing Of Composite Carbon-Fiber Sandwich Panels For Automotive Racing Vehicles, Erik Eckberg

Materials Engineering

Composite sandwich panels were constructed with 4-ply plain weave carbon-fiber/epoxy face sheets in the 0^o/45^o/0^o/45^o orientation and 1/8^th inch Nomex honeycomb core. The panels were cut into 5-inch square test plates for mechanical testing. All testing was done on a fixture designed and fabricated by Pratt & Miller Engineering and installed on an Instron testing system at Cal Poly. The twist test was performed by supporting diagonal corners of the plate while simultaneously loading the opposite two corners at a crosshead rate of .06 in/min (ASTM 3044-94R11). Out of 10 panels tested, …

Corrosion Of Stainless Steel 316l And Astm F75 Cobalt Chromium Alloy During Immersion Testing In Silver Salt Solutions, Meagan Higgins

Materials Engineering

This study evaluates the potential effects of silver salts on biocompatible metals used for prostheses during the chemical reduction process to produce a silver antimicrobial layer on the metal’s surface. Samples of two biocompatible metals were obtained: Stainless Steel 316L and ASTM F75 Cobalt Chromium Alloy. Three different silver salts were also acquired: silver nitrate, silver sulfadiazine, and silver chloride. Specimens of each metal were cut to size using a 4-1/2 inch aluminum oxide, 40 grit, cut off wheel for metal, attached to a Dewalt Angle Grinder. The biocompatible metal samples were then subject to either Solution 1, water with …

Fabricating Replacement Glass Prisms For The Piedras Blancas Lighthouse, Daniel Garcken

Materials Engineering

The objective of this project was to design and create a process for manufacturing replacement glass prisms for the Piedras Blancas lighthouse and several other lighthouses nationwide. The prisms were designed to be in multiple metal arrays spread across the floor of the beacon room (the topmost room of the lighthouses). The prisms functioned to transmit extra, radiant light from the beacon light through the floor of the beacon room and disperse it into the maintenance room below. Using computer aided drafting (CAD) software, an original prism was measured and modeled; the corresponding mold was also modeled. G-codes for controlling …

An Exploratory Investigation Into How Cold Working Can Affect The Acoustic Performance Of Thin Aluminum Foil In A Ribbon Microphone, Alexander (Alex) Stanley

Materials Engineering

Ribbons of 4 μm thin 99.1% pure aluminum foil were cut and corrugated to replace the stock ribbon in an Apex 205 ribbon microphone. Prior to corrugation, half of the ribbons were sandwiched between two KimWipes and two pieces of cardstock then hammered to impart strain hardening. Each ribbon was placed into the microphone capsule and the frequency response of each ribbon was measured. A 10 second sine sweep from 20-20,000 Hz was played through a KRK Rokit 5 speaker and recorded through a ribbon microphone placed 6 inches away from the speaker cone. The signal generated by the ribbon …

The Synthesis And Characterization Of Gold And Silver Nanoparticles In Formal And Informal Settings, Mathew Wynn

Materials Engineering

Silver nanoparticles were synthesized through the reduction of AgNO3 using NaBH4. The borohydride anions were adsorbed onto silver nanoparticles. The repelling forces of the borohydride anions prevented the aggregation of particles, but the addition of an electrolyte or agitation induced aggregation. A yellow hue was given off by the silver nanoparticle sol that, using a spectrophotometer, had plasmon resonance at 386 nm. The silver nanoparticles were estimated to be 10 to 20 nm in diameter. Gold nanoparticles were synthesized through the reduction of HAuCl4 using Na3C6H5O7. The gold nanoparticle sol gave off a red hue that had plasmon resonance at …

Analyzing The Corrosion Resistance Of Ni-Shield 200 Coatings At Different Temperatures When Exposed To Sulphuric Acid, Alex Hussinger

Materials Engineering

Six steel samples each were twin wire arc sprayed with Hastelloy C-276 or Nickel-Shield 200 coatings approximately 0.020″ thick. These samples were then cut into 3″ by 3″ squares. A 2″ diamond grit hole saw was used to abrade and polish to a smooth surface a ring in the middle in order to get an O-ring mechanical seal. The samples were then weighed and loaded into a jig that started from the bottom up with a stainless steel plate, then the sample, then a Viton O-ring, a ¾″ thick glass plate with a 1 3/4″ hole cut in it, another …

Deposition, Characterization, And Fabrication Of A Zinc Oxide Piezoelectric Thin Film Microspeaker Using Dc Reactive Sputtering, Adam Olzick

Master's Theses

A piezoelectric microspeaker device that could be used in a variety of acoustic applications was designed and fabricated using a thin film ZnO layer that was reactively DC sputtered onto a single crystalline n-type silicon substrate. When tested the microspeaker did not produce sound due to complications in the etching process, the thickness of the diaphragms, and clamping effects. Instead, a characterization approach was taken and the structural, optical, electrical, and piezoelectric properties of the ZnO were investigated. Scanning electron microscopy, x-ray diffraction, and atomic force microscopy were utilized to discover the ZnO’s structural properties. Using the XRD and SEM, …

Blunt Impact Performance Evaluation Of Helmet Lining Systems For Military And Recreational Use, Jaclyn Siniora, Ryan Taylor, Darren Suey

Industrial Technology and Packaging

With the increasing problem in collegiate athletes experiencing injuries to the brain, different helmet liners where put to the test to see which liner provided athletes the greatest protection under specific conditions.

This senior project evaluates five different liners in football helmets. Each of the helmet liners were tested at three different temperatures: hot, cold, and ambient. Each helmet had seven different impact locations which were put to the test. The project was designed to be used to test ACH military combat liners as well. Due to shipping bottle necks the ACH combat liners have been left to future Cal …

Correlation Between 90o Tensile And 90o Flexural Properties For Thermoplastic Based Carbon-Fiber Composites, Amy Lautenbach

Materials Engineering

Thermoplastic matrix composites containing carbon fibers and 4 different resins (TP 1-TP 4) were tested in tension with the fibers at 90 degree to the longitudinal axis following ASTM D 3039-00. The tensile strengths varied from 5.07-13.87 ksi with TP 1 as the strongest, and TP 4 as the weakest. SEM images were taken of the fracture surface of the samples to explore the fiber-matrix interaction. The SEM images showed significantly more wetting of the fibers in the higher strength materials. The SEM images of the two stronger materials showed resin coating the fibers even after fracture while the two …

Compatibility Evaluation Of Glass/Epoxy Insulation For Use In Iter’S Central Solenoid Superconducting Electromagnets, Carolyn Grace Kidwell

Masters Theses

A variety of glass fiber types are being considered for use as insulation material in the central solenoid superconducting electromagnets for the International Thermonuclear Experimental Reactor (ITER). Before these materials can be used, a compatibility of these glass products with an epoxy matrix has to be characterized. In this study, three candidate glass types (1581, 7781, and 38050) were considered and their compatibility with a DGEBF epoxy matrix was determined via three-point flexure tests at room temperature (295K) and liquid nitrogen temperature (77K) and constant load flexure creep tests at room temperature. The material variables among these glass products were …

A Semi-Empirical Model To Predict The Acoustic Behaviour Of Fully And Partially Reticulated Polyurethane Foams Based On Microstructure Properties, Olivier Doutres Ph.D., Noureddine Atalla

Olivier Doutres Ph.D.

This work investigates the links between the microstructure of polyurethane foams and their sound absorbing efficiency, and more specifically the effect of membranes closing the cells. In a previous work, the authors proposed a semi-empirical approach to link the foam microstructure properties, i.e. reticulation rate, strut length and thickness, with its non-acoustic parameters. The study was based on the complete characterization of 15 isotropic polyurethane foams with various cell sizes and reticulation rates (i.e. open pore content). This paper proposes a validation of this semi-empirical model using 3 new polyurethane foams, not used in the first characterization set. More importantly, …