Open Access. Powered by Scholars. Published by Universities.®

Materials Science and Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Air Force Institute of Technology

Discipline
Keyword
Publication Year
Publication
Publication Type

Articles 181 - 210 of 329

Full-Text Articles in Materials Science and Engineering

Effects Of Contact Load On The Fretting Fatigue Behavior Of In-100 At Elevated Temperature, Alfred G. Traylor Ii Mar 2009

Effects Of Contact Load On The Fretting Fatigue Behavior Of In-100 At Elevated Temperature, Alfred G. Traylor Ii

Theses and Dissertations

This thesis studied the effects of contact load of 8006 N on the fretting fatigue behavior of IN-100 at an elevated temperature of 600°C. First, S-N curves were created for a range of applied axial stresses at an identical stress ratio of 0.03 at 8006 N. A condition of partial slip condition necessary to fretting fatigue was verified by generating hysteresis loops, plotting shear force against axial stress. The half-contact width and the crack initiation location were determined for all of the fretting specimens using optical and scanning electron microscopes. The contact widths were consistent with expected analytical values and …

Go to article

Ceramic Matrix Composite Characterization Under A Combustion And Loading Environment, Andrew R. Nye Mar 2009

Ceramic Matrix Composite Characterization Under A Combustion And Loading Environment, Andrew R. Nye

Theses and Dissertations

Lightweight materials that can withstand high temperatures and corrosive environments are constantly sought after in the aerospace industry, typically for Gas Turbine Engine (GTE) application. These materials need to retain their strength throughout the long service period they would see in the combustor and turbine components of a GTE. One material that is ideal for these types of applications is an oxide/oxide Ceramic Matrix Composite (CMC). The fatigue behavior of the oxide/oxide CMC NextelTM 720/Alumina (N720/A) was investigated in a unique high temperature environment. N720/A consisted of an 8-harness satin weave of NextelTM aluminum oxide/silicon oxide fibers bound …

Go to article

Production And Characterization Of High Repetition Rate Terahertz Radiation In Femtosecond-Laser-Induced Air Plasma, Michael L. Dexter Mar 2009

Production And Characterization Of High Repetition Rate Terahertz Radiation In Femtosecond-Laser-Induced Air Plasma, Michael L. Dexter

Theses and Dissertations

The purpose of this research was to produce and characterize high repetition rate terahertz radiation in ionized air plasma. An 800 nanometer, 50 femtosecond, 0.35 Watt, 40 KHz, pulsed Ti:Sapphire laser system was used as the source infrared beam. This beam was focused onto a second harmonic generation crystal to produce a collinear, perpendicularly polarized secondary beam at 400 nm. After realigning the polarization of the fundamental to the second harmonic and compensating for group velocity dispersion introduced by the optics, both beams were recombined and focused by a 3.75 cm focal length mirror to form an air plasma. An …

Go to article

A Comparative Study Of The Bidirectional Reflectance Distribution Function Of Several Surfaces As A Mid-Wave Infrared Diffuse Reflectance Standard, Bradley Balling Mar 2009

A Comparative Study Of The Bidirectional Reflectance Distribution Function Of Several Surfaces As A Mid-Wave Infrared Diffuse Reflectance Standard, Bradley Balling

Theses and Dissertations

The Bi-Directional Reflectance Distribution Function (BRDF) has a well defined diffuse measurement standard in the ultraviolet, visible, and near infrared (NIR), Spectralon(trade name). It is predictable, stable, repeatable, and has low surface variation because it is a bulk scatterer. In the mid-wave IR (MWIR) and long-wave IR (LWIR), there is not such a well-defined standard. There are well-defined directional hemispherical reflectance (DHR) standards, but the process of integrating BRDF measurements into DHR for the purpose of calibration is problematic, at best. Direct BRDF measurement standards are needed. This study use current calibration techniques to ensure valid measurements and then systematically …

Go to article

Wave Optics Simulation Of Optically Augmented Retroreflections For Monostatic/Bistatic Detection, John J. Tatar Iii Mar 2009

Wave Optics Simulation Of Optically Augmented Retroreflections For Monostatic/Bistatic Detection, John J. Tatar Iii

Theses and Dissertations

Optical devices interrogated with a laser in the appropriate band can exhibit strong, deterministic reflections of the incident beam. This characteristic could be exploited for optical target detection and identification. The distribution of reflected power is strongly dependent on the geometry of the interrogation scenario, atmospheric conditions, and the cross section of the target optical device. Previous work on laser interrogation systems in this area has focused on analytic models or testing. To the best of my knowledge, I am presenting for the first time an approach to predict reflected power for a variety of interrogation configurations, targets, and propagation …

Go to article

Nondestructive Evaluation Of Aircraft Composites Using Terahertz Time Domain Spectroscopy, Christopher D. Stoik Dec 2008

Nondestructive Evaluation Of Aircraft Composites Using Terahertz Time Domain Spectroscopy, Christopher D. Stoik

Theses and Dissertations

Terahertz (THz) time domain spectroscopy (TDS) was assessed as a nondestructive evaluation technique for aircraft composites. Material properties of glass fiber composite were measured using both transmission and reflection configuration. The interaction of THz with a glass fiber composite was then analyzed, including the effects of scattering, absorption, and the index of refraction, as well as effective medium approximations. THz TDS, in both transmission and reflection configuration, was used to study composite damage, including voids, delaminations, mechanical damage, and heat damage. Measurement of the material properties on samples with localized heat damage showed that burning did not change the refractive …

Go to article

The Effect Of Radiation On The Electrical Properties Of Aluminum Gallium Nitride/Gallium Nitride Heterostructures, John W. Mcclory Jun 2008

The Effect Of Radiation On The Electrical Properties Of Aluminum Gallium Nitride/Gallium Nitride Heterostructures, John W. Mcclory

Theses and Dissertations

AlGaN/GaN Heterojunction Field Effect Transistors (HFETs) were irradiated at low temperature and the temperature dependent changes to drain current, gate current, capacitance, and transconductance were measured. The results were compared to the charge control model of the drain current and trap-assisted tunneling model of the gate current to determine the source of the radiation-induced changes. AlGaN/GaN HFETs demonstrated threshold voltage shifts and drain current changes after irradiation. After electron and neutron irradiation applied at ~80 K, measurement of the drain current at this temperature showed an increase that saturated after 1013 electrons/cm2 or 1010 neutrons/cm2 due …

Go to article

Analysis Of Multi-Layered Materials Under High Velocity Impact Using Cth, Jason K. Lee Mar 2008

Analysis Of Multi-Layered Materials Under High Velocity Impact Using Cth, Jason K. Lee

Theses and Dissertations

Multi-layer armor containing ceramic and metallic layers has become more common in the past two decades. Typically, ceramics have high compressive strength which combined with their low density make them highly desirable for armor applications. This research effort numerically simulates high velocity impact of cylindrical projectiles on multi-layer metallic and ceramic targets of finite thickness. The impact of the projectile occurs normal to the surface of the target. The projectiles used are made of either S7 tool steel or tungsten. The targets consist of either rolled homogeneous armor, 4340 steel and boron carbide ceramic or rolled homogeneous armor and boron …

Go to article

Effects Of Environment On Creep Behavior Of Nextel 720/Alumina-Mullite Ceramic Composite At 1200°C, Christopher L. Genelin Mar 2008

Effects Of Environment On Creep Behavior Of Nextel 720/Alumina-Mullite Ceramic Composite At 1200°C, Christopher L. Genelin

Theses and Dissertations

The creep behavior of an oxide-oxide ceramic matrix composite (CMC) was investigated at 1200°C in laboratory air, in steam and in argon. The composite consisted of a porous alumina-mullite matrix reinforced with laminated, woven mullite/alumina (Nextel/720) fibers. The composite had no fiber coating and relied on its porous alumina/mullite matrix for flaw tolerance. Tensile stress-strain behavior was investigated and the tensile properties were measured at 1200°C in laboratory air. Tensile creep behavior of the CMC was examined for creep stress levels of 73, 91, 114 and 136 MPa. Creep run-out, set to 100 h, was achieved for stress levels ≤ …

Go to article

Electrical Activation Studies Of Silicon Implanted Aluminum Gallium Nitride With High Aluminum Mole Fraction, Elizabeth A. Moore Dec 2007

Electrical Activation Studies Of Silicon Implanted Aluminum Gallium Nitride With High Aluminum Mole Fraction, Elizabeth A. Moore

Theses and Dissertations

This research demonstrates a method for producing highly conductive Si-implanted n-type aluminum gallium nitride (AlxGa1-xN) alloys, and represents a comprehensive analysis of the resulting material's electrical and optical properties as a function of Al mole fraction, anneal temperature, anneal time, and implantation dose. Highly conductive alloys are critical to the fabrication of devices operating in deep UV, high-temperature, high-power, and high-frequency environments, and thus this research is significant in regard to the application of such devices. The AlxGa1-xN wafers of this study, with Al concentrations of 10 to 50%, were implanted at …

Go to article

Radio Frequency Mems Switch Contact Metal Selection, Ronald A. Coutu Jr., Paul E. Kladitis, Robert L. Crane, Kevin D. Leedy Jun 2007

Radio Frequency Mems Switch Contact Metal Selection, Ronald A. Coutu Jr., Paul E. Kladitis, Robert L. Crane, Kevin D. Leedy

AFIT Patents

A method for selecting metal alloys as the electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This method includes a review of alloy experience, consideration of equilibrium binary alloy phase diagrams, obtaining thin film material properties and, based on a suitable model, predicting contact electrical resistance performance. After determination of a candidate alloy material, MEMS switches are conceptualized, fabricated and tested to validate the alloy selection methodology. Minimum average contact resistance values of 1.17 and 1.87 ohms are achieved for micro-switches with gold (Au) and gold-platinum (Au-(6.3 at %)Pt) alloy contacts. In addition, `hot-switched` life cycle test results …

Go to article

Effect Of Prior Aging On Fatigue Behavior Of Im7/Bmi 5250-4 Composite At 191°C, Christine G. Ladrido Jun 2007

Effect Of Prior Aging On Fatigue Behavior Of Im7/Bmi 5250-4 Composite At 191°C, Christine G. Ladrido

Theses and Dissertations

IM7/BMI 5250-4 with carbon fiber orientations [± 45] and [0/90] were aged in air at 191 °C for up to 1000 hours. The weight loss was analyzed during the aging process. Tension to failure tests were performed on both the unaged and aged specimens to establish a baseline for the Ultimate Tensile Strengths and Young's Modulus. Tension-tension cyclic load fatigue testing was conducted on the specimen to determine the effect of prior aging on the fatigue response of the composite. Cyclic strain accumulation was not influenced by prior aging, but it was influenced by the stress levels applied. [± 45] …

Go to article

High Temperature Degradation Of 5250-4 Polymer Resin, Patrick E. Link Jun 2007

High Temperature Degradation Of 5250-4 Polymer Resin, Patrick E. Link

Theses and Dissertations

5250-4 bismaleimide resin is used in high performance polymer matrix composites with high temperature aeronautical applications. This thesis investigated the thermal and oxidative degradation of 5250-4 neat resin powder in argon, air, and oxygen environments. The powder was aged at 163 deg. C, 177 deg. C, and 190 deg. C in all environments for at least 250 hours. Isothermal thermo-gravimetric analysis demonstrated that weight loss was negligible for aging in the argon environment, indicating weight loss is the result of an oxidative process at these temperatures. The 5250-4 powder exhibited an initial period of weight gain before eventually losing weight …

Go to article

Optical Parametric Oscillation In Orientation-Patterned Gallium Arsenide, Scott A. Shell Mar 2007

Optical Parametric Oscillation In Orientation-Patterned Gallium Arsenide, Scott A. Shell

Theses and Dissertations

Tunable laser sources in the mid-infrared (MIR) spectral range are required for several Air Force applications. Existing lasers with output in the near-infrared can be converted to more desirable MIR by using nonlinear effects. Orientation patterned gallium arsenide (OPGaAs) is a promising nonlinear conversion material because it has broad transparency and can be engineered for specific pump laser and output wavelengths using quasi-phase matching techniques. This research examines optical parametric oscillation (OPO) of several OPGaAs samples using a 2.052 micrometers wavelength Tm, Ho:YLF pump laser. Of the seven samples available the five that were capable of getting OPO output with …

Go to article

Cobalt Doping Of Semiconducting Boron Carbide Using Cobaltocene, Lonnie Carlson Mar 2007

Cobalt Doping Of Semiconducting Boron Carbide Using Cobaltocene, Lonnie Carlson

Theses and Dissertations

The decomposition of cobaltocene and metacarborane (closo-1,7-dicarba-decaborane) under low energy electron irradiation at about 200 K results in a material with the Fermi level closer to the valence band than the material resulting from the decomposition of metacarborane alone. This indicates that cobaltocene provides a relatively p-type dopant as seen in ultraviolet photoemission spectroscopy/inverse photoemission spectroscopy. Upon warming to room temperature, however, the Fermi level shifts towards the conduction band, suggesting an n-type dopant. This temperature dependent surface photovoltage effect is not compelling evidence for the majority carrier type but does suggest an increase in the carrier concentration …

Go to article

Characterization Of Intercalated Graphite Fibers For Microelectromechanical Systems (Mems) Applications, Bryan W. Winningham Mar 2007

Characterization Of Intercalated Graphite Fibers For Microelectromechanical Systems (Mems) Applications, Bryan W. Winningham

Theses and Dissertations

Research was accomplished to characterize the electrical and physical characteristic changes of the Thornel® P-100 carbon fiber and five variants when intercalated with 96% sulfuric acid and incorporated the use of Microelectromechanical Systems (MEMS) structures for testing purposes. The five fiber variants were oxidized in 1 M nitric acid at 0.5 A for 30 seconds, 1 and 2 minutes, the last two samples were detreated at 1150 °C for one hour prior to the nitric acid treatment. The fibers were mounted onto a MEMS die, placed into a chip carrier, sulfuric acid added, the chip carrier sealed and testing accomplished. …

Go to article

An Exploration Of Several Structural Measurement Techniques For Usage With Functionally Graded Materials, Robert A. Reuter Dec 2006

An Exploration Of Several Structural Measurement Techniques For Usage With Functionally Graded Materials, Robert A. Reuter

Theses and Dissertations

Titanium / titanium boride functionally graded 6"x 1"x1" beams were subjected to a four-point beam test in order to critique the value of several measurement techniques. Also, finite element analysis results were compared with experimental values and general observations about the experiment were recorded. Uniform 85% TiB /15% Ti and uniform commercially pure titanium specimens were also subjected to the same loading conditions as a control. Techniques used include digital image correlation, fiber optic strain gauging, strain gauging, and differential infrared thermography techniques. The strain data results were compared with one another and to linear finite element models. It was …

Go to article

Modeling Fracture In Z-Pinned Composite Co-Cured Laminates Using Smeared Properties And Cohesive Elements In Dyna3d, Jason K. Freels Sep 2006

Modeling Fracture In Z-Pinned Composite Co-Cured Laminates Using Smeared Properties And Cohesive Elements In Dyna3d, Jason K. Freels

Theses and Dissertations

The purpose of the present research was three-fold: 1) gain a more sophisticated understanding of the response of co-cured composite joints with and without through-thickness reinforcement (TTR), 2) compare the behavior of specimens reinforced with various sizes and densities of reinforcement, and 3) use experimental data to verify the existing DYNA3D smeared property model. Double cantilever beam, end-notch flexure and T-section specimens reinforced with 0.011" diameter z-pins at 2% and 4% volume densities were tested to determine the mode I, mode II and mixed mode (I and II) behavior. Results were added to preliminary research in which tests were conducted …

Go to article

Effects Of Environment On Creep Behavior Of Two Oxide-Oxide Ceramic Matrix Composites At 1200°C, Pavlos Koutsoukos Sep 2006

Effects Of Environment On Creep Behavior Of Two Oxide-Oxide Ceramic Matrix Composites At 1200°C, Pavlos Koutsoukos

Theses and Dissertations

Previous studies by the advisor and graduate students examined creep behavior of the Nextel720/Alumina CMC in air and in 100% steam environments at 1200 and 1330°C. Results showed that while this oxide/oxide system exhibits an exceptionally high fatigue limit at 1200°C it also experiences substantial strain accumulation under sustained loading conditions. Furthermore, these earlier investigations revealed a significant degrading effect of 100% steam environment on material performance under both static and cyclic loadings. The present effort will investigate creep rupture behavior of Nextel720/Alumina composite in the inert gas environment. In addition, creep rupture behavior of Nextel720/Aluminosilicate CMC will be investigated …

Go to article

Effects Of Polishing Shot-Peened Surfaces On Fretting Fatigue Behavior Of Ti-6al-4v, Kasey S. Scheel Sep 2006

Effects Of Polishing Shot-Peened Surfaces On Fretting Fatigue Behavior Of Ti-6al-4v, Kasey S. Scheel

Theses and Dissertations

The research of this thesis was done to investigate the effects of polishing a shot-peened specimen of Ti-6Al-4V on the fretting fatigue life of that specimen. The shot-peening process, though one of the most beneficial techniques in prolonging fretting fatigue life, creates a textured surface that may lead to problems on the micro level. This research was done in an attempt to further improve the peening process by examining the effects of another surface treatment to be used in conjunction, surface polishing. The rough peened surface may contain abrupt changes in surface geometry that act as stress risers, which are …

Go to article

Characterization Of Passivated Indium Antimonide, Catherine Ann Taylor Jun 2006

Characterization Of Passivated Indium Antimonide, Catherine Ann Taylor

Theses and Dissertations

Infrared absorption and photoluminescence measurements have been used to optically characterize bulk-grown, 680-μm thick, indium antimonide (InSb), both as-grown and after passivation by either anodization or a 700-Å layer of silicon oxide (SiOx). Spectra were obtained using Fourier transform infrared (FT-IR) spectroscopy. Results include the effects of sample temperature in the range of 10 to 300 K and 4.636 μm laser pump power in the range of 28 mW to 1.43 W for the photoluminescence spectrum.

Go to article

Effect Of Environment On Creep Behavior Of An Oxide/Oxide Cfcc With ±45° Fiber Orientation, Gregory T. Siegert Jun 2006

Effect Of Environment On Creep Behavior Of An Oxide/Oxide Cfcc With ±45° Fiber Orientation, Gregory T. Siegert

Theses and Dissertations

Aerospace applications require materials capable of maintaining superior mechanical properties while operating at high temperatures and oxidizing environments. Nextel™ 720/A (N720/A), an oxide/oxide ceramic matrix composite (CMC) with a porous alumina matrix was developed specifically to provide improved long-term properties and performance at 1200°C. This research evaluated the creep behavior of N720/A with a ±45° fiber orientation at 1200°C in: laboratory air, steam, and argon environments. Creep-rupture tests at the creep stress levels of: 45, 40, 35, and 15 MPa were conducted in each environment.
The ultimate tensile strength of N720/A with ±45° fiber orientation was 55 MPa, the elastic …

Go to article

Wear Analysis Of Cu-Al Coating On Ti-6al-4v Under Fretting, Karl N. Murray Jun 2006

Wear Analysis Of Cu-Al Coating On Ti-6al-4v Under Fretting, Karl N. Murray

Theses and Dissertations

The effects of changes in the coefficient of friction (CoF) between the contacting surfaces on the fretting wear characteristics of Cu-Al coating on Ti-6Al-4V were investigated. This Cu-Al coating is part of a system that is applied to titanium turbine blades to reduce fretting at the interface. In the application, there is a solid lubricant that is added on top of the coating as an assembly aid and to help reduce the friction while the lubricant remains within the contact. Previous studies have researched the characteristics of the coating without the additional lubricant. In this study, liquid motor oil was …

Go to article

Effects Of Frequency And Environment On Fatigue Behavior Of An Oxide-Oxide Ceramic Matrix Composite At 1200°C, Griffin Hetrick Jun 2006

Effects Of Frequency And Environment On Fatigue Behavior Of An Oxide-Oxide Ceramic Matrix Composite At 1200°C, Griffin Hetrick

Theses and Dissertations

Advances in aeronautical engineering in the 21st century depend upon materials that can perform well in extreme environments such as high temperatures and oxidizing conditions. Nextel™720/Alumina (N720/A) is an oxide/oxide ceramic matrix composite with a porous alumina matrix that has been identified as a candidate material for such applications. This research investigated the effects of frequency on fatigue response of N720/A at 1200°C in both air and steam environment. Prior investigation of this material by Eber [8] in 2005 studied fatigue behavior at 1200°C in air and in steam environments at the frequency of 1.0 Hz. The current research focused …

Go to article

Optical Characterization Of Thick Growth Orientation-Patterned Gallium Arsenide, Joshua W. Meyer Mar 2006

Optical Characterization Of Thick Growth Orientation-Patterned Gallium Arsenide, Joshua W. Meyer

Theses and Dissertations

Tunable laser sources in the mid-infrared (MIR) spectral range are required for several Air Force applications. Existing lasers with output in the near-infrared can be converted to more desirable MIR by using nonlinear effects. Orientation patterned gallium arsenide (OPGaAs) is a promising nonlinear conversion material because it has broad transparency and can be engineered for specific pump laser and output wavelengths using quasi-phase matching techniques. This research examines the optical quality of seven OPGaAs crystal samples and explores the design of an optical parametric oscillator (OPO) device. The Air Force Research Laboratory Electro-Optical Countermeasures Technology Branch obtained the samples from …

Go to article

Characterization Of Stress In Gan-On-Sapphire Microelectromechanical Systems (Mems) Structures Using Micro-Raman Spectroscopy, Francisco E. Parada Mar 2006

Characterization Of Stress In Gan-On-Sapphire Microelectromechanical Systems (Mems) Structures Using Micro-Raman Spectroscopy, Francisco E. Parada

Theses and Dissertations

Micro-Raman (µRaman) spectroscopy is an efficient, non-destructive technique widely used to determine the quality of semiconductor materials and microelectromechanical systems. This work characterizes the stress distribution in wurtzite gallium nitride grown on c-plane sapphire substrates by molecular beam epitaxy. This wide bandgap semiconductor material is being considered by the Air Force Research Laboratory for the fabrication of shock-hardened MEMS accelerometers. µRaman spectroscopy is particularly useful for stress characterization because of its ability to measure the spectral shifts in Raman peaks in a material, and correlate those shifts to stress and strain. The spectral peak shift as a function of stress, …

Go to article

Passive Multiple Beam Combination In Optical Fibers Via Stimulated Brillouin Scattering, Kirk C. Brown Mar 2006

Passive Multiple Beam Combination In Optical Fibers Via Stimulated Brillouin Scattering, Kirk C. Brown

Theses and Dissertations

Many active methods of scaling laser brightness have been demonstrated in recent years. The goal of this research was to demonstrate the feasibility of passively combining multiple laser beams using Stimulated Brillouin Scattering (SBS) in a long multimode optical fiber. This method of combination employed a “Gatling gun” fiber array that allowed several collimated beams to be focused by a lens into an optical fiber. The retroreflected Stokes beam is passed through the center of the beam combiner for analysis. In addition to experimental methodology and equipment used, the theoretical and historical background of SBS in optical fibers is provided. …

Go to article

Analysis Of Photoconductive Properties In Ge2Sb2Te5 (Gst) Chalcogenide Films For Applications In Novel Electronics, John R. V. Chezem Mar 2006

Analysis Of Photoconductive Properties In Ge2Sb2Te5 (Gst) Chalcogenide Films For Applications In Novel Electronics, John R. V. Chezem

Theses and Dissertations

This thesis investigated the thermal phase-change properties in Ge2Sb2Te5 (GST) chalcogenide-based films and determined the feasibility of coupling the GST with photosensitive DNA material for novel optical device applications. Modeling and testing of GST were researched with the approach that GST would react as a resistive mechanism through thermal manipulation. A test structure was fabricated with a 2-micronmeter MEMS fabrication process. GST material was deposited (by RF sputtering) on the surface of the test structures. The GST was analyzed primarily in the amorphous to crystalline transition states due to more distinct changes in the resistance …

Go to article

Validation Of A Scaled Plane Strain Hypervelocity Gouging Model, Ronald J. Pendleton Mar 2006

Validation Of A Scaled Plane Strain Hypervelocity Gouging Model, Ronald J. Pendleton

Theses and Dissertations

The phenomenon of high speed impact is of great interest to the Air Force of Scientific Research and the Air Force Research Laboratory's Holloman High Speed test track. Rocket sled tests at the facility frequently are limited to velocities lower than actually attainable due to damage to the rail in the form of gouges. Direct observation of the gouging phenomenon is not currently possible. This leaves computational modeling as the only means to study the phenomenon. A computer model has previously been used to model the development of gouging at the Holloman High Speed Test Track. However, this model has …

Go to article

Characterization Of Functionally Graded Materials, Benjamin D. Chapman Mar 2006

Characterization Of Functionally Graded Materials, Benjamin D. Chapman

Theses and Dissertations

The purpose of this study was to characterize the behavior of a functionally graded material through experimentation and analytical modeling. Functionally graded materials are a ceramic metal composite which transitions from metal on one face to ceramic on the opposite face. Creating reliable models required verifying the material properties. This was accomplished through the use of a static modulus of elasticity test as well as a dynamic ping test. The natural frequencies from the dynamic test were compared with finite element models to determine which material properties most accurately represented the functionally graded material. It was found that the material …

Go to article

First Prev Next Last