Materials Science and Engineering Commons^™

High-Temperature Ceramic Coatings Used In Aero Engine Environments, David Rickerby, Paul Morrell, Matthew Hancock

Thermal Barrier Coatings IV

This paper reviews the role of ceramic coatings technology in the hot sections of modern gas turbine engines by contrasting the role of surface engineering and coatings away from secondary reliance (i.e. the coating extending the life of the component and when the coating is lost or fails there is still an appreciable remnant life of the component) to prime reliance where the failure of the coating would result in a rapid failure of the component. To illustrate this change in design philosophy, the coating systems deployed in the HP turbine module in both shrouded and unshrouded configurations are discussed …

Fate And Transport Of Nanohybrids In Subsurface Media For Oil Field Applications, M.J. Kadhum, D.P. Swatske, J.H. Harwell, D.E. Resasco, B.J. Shiau

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

Interfacially active carbon nanotube hybrids have potential to be used in reservoir development applications. Carbon nanotubes hybrids (CNT) can act as carriers for catalytic nanoparticles into regions far inside the reservoir; they have the ability to stabilize water/oil interface in emulsions or can be used as contrast agents or sensors. One of the main challenges for successful utilization of these nanoparticles is the difficulty associated with stabilizing their dispersions and propagating them through the wellbore rock or deep inside the reservoir in harsh reservoir conditions of salinity and temperature. In this work, CNT were dispersed in high salinity brine using …

Particles Migrating And Plugging Mechanism In Loosen Sandstone Heavy Oil Reservoir And The Strategy Of Production With Moderate Sanding, Yiting Xie, Zhaohui Chen, Fujie Sun

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

Fine rock particles is easy to be suspended and carried in loosen sandstone heavy oil reservoir due to the higher density and viscosity of heavy oil. The sand particles settle down, bridge and clog in pore and throat, as the result, the filtration resistance in reservoir will be redistributed. It significantly impacts on the well productivity. In this paper, the process of sand particles transporting and clogging in tunnels of rock is observed utilizing a microscopic visualization model with the unconsolidated sandpack. Furthermore, the mechanism of fine particles migration and clogging and the effects to percolation capacity of porous medium …

The Effect Of Exposure Variables On The Development Of Alumina Scales, Gerry Meier

Thermal Barrier Coatings IV

The early development of an adherent, slowly-growing α-alumina film on the bond coat is a critical factor in the life of a thermal barrier coating system. This presentation will include results of recent experiments at the University of Pittsburgh and reanalysis of older data from the literature on the selective oxidation of aluminum from Ni-base alloys. The following aspects of alumina scale establishment will be addressed: • The manner by which alloy composition affects the kinetics and mechanism of the transition of alumina from the θ to the α polymorph. • The influence of the θ to α transition on …

Design Constraints And Higher Temperature Intermetallic Bond Coatings, T.M. Pollock, D. Jorgensen, R.W. Jackson, M. He, A. Suzuki, D. Lipkin

Thermal Barrier Coatings IV

Bond coat interlayers in thermal barrier coating (TBC) systems must perform reliably in the complex thermal, chemical and mechanical environment of the turbine engine. To achieve higher temperatures and /or longer cyclic lives, a spectrum of intrinsic failure modes must be suppressed. Failure may occur at the bond coat – thermally grown oxide (TGO) interface, at the TGO-TBC interface or by oxidation-enhanced propagation of cracks from the coating into the substrate. Models for the failure processes suggest that bond coatings should possess improved high temperature strength (creep resistance), low oxide growth stresses and high interfacial toughnesses. Oxide growth stresses have …

Cold Spray Bond Coats Structure And Oxidation Behavior, A. Barth, S. Kudapa, W. Wong, K. Onizawa

Thermal Barrier Coatings IV

No abstract provided.

Preface, Engineering Conferences International

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

No abstract provided.

Program, Engineering Conferences International

5th International Conference on Porous Media and Their Applications in Science, Engineering and Industry

No abstract provided.

Program, Franco Berruti

Thermal Barrier Coatings IV

No abstract provided.

Analysis Of Critical Behavior In Magnetic Materials, Dustin David Belyea

USF Tampa Graduate Theses and Dissertations

This work contains a broad study of a variety of magnetic materials undergoing second order phase transitions. In general this leads to an overall increase in information and analytical methods to further the field of magnetocalorics. Specifically, critical aspects of magnetocaloric materials were compared within systems in relation to structure, stoichiometry, magnetic minority phases and magnetic contaminants. Detailed analyses were developed to quantify techniques which were in the past used mainly in a qualitative way, leading to a more complete understanding of how critical phenomena impacts the magnetocaloric response.

A Comparative Study Of Commercially Available Comfort Fabrics, Melinda Elizabeth Finnie

Master's Theses and Doctoral Dissertations

The comfort fabric market continues to grow and become more competitive. Consumers expect their active wear to deliver performance beyond simply being a barrier between their body and the environment. Textile manufacturers have taken notice, and there is a wide range of comfort fabrics on the market. This research tests fabric samples from leading comfort fabric technologies: phase change materials, nanotechnology, modified fiber structure and blends, as well as the original comfort fiber, cotton. The most widely recognized comfort fabric properties concern the thermal and moisture management of a fabric. Using a guarded sweating hot plate, standardized test methods, and …

Creating A Stem Identity: Investment With Return, Janet Callahan, Patricia Pyke, Susan Shadle, R. Eric Landrum

Materials Science and Engineering Faculty Publications and Presentations

Establishing a strong STEM (science, technology, engineering and mathematics) identity at Boise State University, a metropolitan campus with approximately 3,655 undergraduate STEM students and a total undergraduate enrollment of approximately 19,042 (16,136 FTE) has been an important step toward creating a climate conducive to facilitating fundamental change. Examples of such change include building collaborations among faculty within and across departments, establishing the identity of students as part of a community beyond their chosen major, improving the efficiency and effectiveness of university systems, and perhaps most importantly, developing a framework to think deliberately about ways to effect change. This paper is …

Experimental Investigation Of Lateral Cyclic Behavior Of Wood-Based Screen-Grid Insulated Concrete Form Walls, John Stuart Garth

Dissertations and Theses

Insulated concrete forms (ICFs) are green building components that are primarily used for residential wall construction. Unlike most polystyrene based ICF variants, the Faswall ICFs used in these experiments were significantly denser because they were made from recycled wood particles and cement. The current design approach for structures constructed with this type of wall form only allows the designer to consider the contribution of the reinforced concrete cores. Previous research has shown that this approach may be conservative. This project experimentally evaluated the lateral structural response of these types of grid ICF walls under increasing amplitude of in-plane cyclic loading. …

Stress Analysis For Chip Scale Packages With Embedded Active Devices Under Thermal Cycling, Hyunwook Yeo

Dissertations and Theses

One of the main challenges in the electronics manufacturing and packaging development is how to integrate more functions inside the same or even smaller size. To meet the demand for higher integration, the interest toward passive and active component embedding has been increasing during the past few years. One of the main reasons for the growing interest toward embedded active components, in addition to demand for higher packaging density, is the need for better electrical performance of the component assemblies. However, it is little known how embedded IC and passives affect the reliability of IC packaging.

Solder joints have been …

Biomechanical Properties Of Hemlocks: A Novel Approach To Evaluating Physical Barriers Of The Plant-Insect Interface And Resistance To A Phloem-Feeding Herbivore, Paul Ayayee, Fuqian Yang, Lynne K. Rieske

Entomology Faculty Publications

Micromechanical properties that help mediate herbivore access may be particularly important when considering herbivorous insects that feed with piercing-sucking stylets. We used microindentation to quantify the micromechanical properties of hemlock, Tsuga spp., to quantify the hardness of the feeding site of the invasive hemlock woolly adelgid, Adelges tsugae. We measured hardness of the hemlock leaf cushion, the stylet insertion point of the adelgid, across four seasons in a 1 y period for four hemlock species growing in a common garden, including eastern, western, mountain, and northern Japanese hemlocks. Leaf cushion hardness was highest in the fall and winter and …

Influence Of Grain Size And Widmanstätten Colonies On Variability Of Tensile Properties Of Forged Ti-6al-4v, Blake T. Gaspar

Master's Theses

When testing forgings for specifications, it was found that some parts did not meet the requirements for mechanical properties. This triggered an investigation into two of the parts from the lot that did not meet specification. The ultimate reason for failure was due to lower than necessary yield strength and ultimate tensile strength values, as well as unwanted variability between regions of the part. Therefore, samples of the regions were tensile tested to determine the differences that existed in yield strength, ultimate tensile strength, and elongation. After tensile testing, quantitative metallography and fractography were conducted to identify aspects of the …

An Investigation Into The Properties And Fabrication Methods Of Thermoplastic Composites, Ann E. Livingston-Peters

Master's Theses

As applications for thermoplastic composites increase, the understanding of their properties become more important. Fabrication methods for thermoplastic composites continually improve to match designs specifications. These advanced thermoplastics have begun to show an improvement in mechanical properties over those found in thermoset composites commonly used in industry. Polyaryletherketones (PEK) have high service temperatures, good mechanical properties, and improved processing capabilities compared to thermoplastics used in the past making them important to the aerospace industry. The wide range of types of PEK make them suitable for a variety of applications, but selection of specific chemistries, processing parameters, and composite stack-ups determine …

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual examination of suspicious regions …

Design, Implementation, And Test Of A Micro Force Displacement System, Evan Derek Cate

Master's Theses

The design and implementation of a micro-force displacement system was completed to test the force-displacement characteristics of square silicon diaphragms with side lengths of 4mm, 5mm, and 7mm with a thickness of 10um. The system utilizes a World Precision Instruments Fort 10g force transducer attached to a World Precession Instruments TBM4M amplifier. A Keithley 2400 source meter provided data acquisition of the force component of the system. A micro prober tip was utilized as the testing probe attached to the force transducer with a tip radius of 5um. The displacement of samples was measured using a Newport M433 linear stage …

Stress Corrosion Cracking In Polymer Matrix Glass Fiber Composites, Jonathan Kosak

Electronic Theses and Dissertations

With the use of Polymer Matrix Glass Fiber Composites ever expanding, understanding conditions that lead to failure before expected service life is of increasing importance. Stress Corrosion Cracking (SCC) has proven to be one such example of conditions found in use in high voltage transmission line applications that leads to brittle fracture of polymer matrix composites.

SCC has been proven to be the result of acid buildup on the lines due to corona discharges and water buildup. This acid leaches minerals from the fibers, leading to fracture at low loads and service life. In order to combat this problem, efforts …

Second Generation Design Of An Operator Independent Teflon Coating Adhesion Tester For Coronary Guidewires, Garrett L. Wong

Materials Engineering

No abstract provided.

Electrochemical Characterization Of Precious Metal Braze Alloys Using Potentiodynamic Polarization, Maxwell Glen Martin, Mason Gregory Morgan, Matthew David Vance

Materials Engineering

This study aimed to characterize the electrochemical behavior of six precious metal braze alloys by performing potentiodynamic polarization tests (ParStat 2273) based on ASTM Specifications G5 and G59. To determine the extent to which the alloys will contribute to galvanic corrosion in a marine environment (3.5 wt% NaCl), corrosion analysis software was used to produce fitted Tafel lines to determine the open circuit potential, V_oc, for each alloy. The V_oc values for the alloys were found to be -66.58 mV for Gold ABA, 13.01 mV for Nicoro^®, -39.00 mV for Nioro^®, 23.4 mV …

Fabrication And Testing Of Arabinan Cellulose Nanocomposites, Ross Johnson, Austin Rosso, Nick Semansky

Materials Engineering

Inspired by the structure and composition of cactus spines found in nature, arabinan-cellulose nanocomposites were fabricated into thin films and tested for mechanical stiffness. The composites consisted of varying amounts of nanocrystalline cellulose reinforcement suspended in an arabinan matrix. Both materials are polysaccharides and are known to be biodegradable and food safe. The thin film samples were tensile tested using a dynamic mechanical analysis machine both as-cast and after a heat-treatment. The heat treatment of the arabinan itself resulted in an order of magnitude increase in stiffness, while the cellulose reinforced composites increased roughly six fold. The arabinan-50 wt% cellulose …

A Process Development Study On Reducing The Anisotropy While Maintaining The Strength Of Extruded Aluminum Alloy 2195 Through Heat Treatment, Theodore James Arehart

Materials Engineering

The purpose of this study was two-fold: develop an aging curve for extruded 2195 aluminum and test the magnitude of the anisotropy in the extrusion throughout the aging process. Two aging curves were developed, one at 290^oF and the other at 320^oF, through hardness tests of aged samples. The hardness was found to change, from approximately 72 HRB to 90 HRB, within the first 6 hours and not change more than 2 HRB in the 42 hours following. It was determined that the 320^oF temperature was more promising due to faster aging time, and …

Manufacture And Mechanical Testing Of Thin Film Composites Composed Of Poly-Lactic Acid And Nanocrystalline Cellulose, Catherine E. Mohan

Materials Engineering

Society’s overuse of petroleum-based plastic products has created a waste problem that is threatening environments around the world. New efforts have been made to find a suitable replacement derived from a renewable source. Poly-lactic acid has become one of the front-runners in this search. It is derived from starches found in potatoes, corn, and other grains. There are many factors that make Poly-lactic acid-based polymers a suitable replacement for petroleum-based ones, but it still suffers from low mechanical strength due to low crystallinity percentages. Doping the polymer with nanocrystalline cellulose provides more nucleation sites for the crystallization of the polymer …

High Cycle Rotating Bending Fatigue Of 6061-T6 Friction Stir Welded Extrusions, John Chang, Travis Miller

Materials Engineering

Fatigue testing was done on friction stir welded joints of 6061-T6 aluminum extrusions. Tests were run using a rotating bending fatigue machine at stresses from 111.5 to 138.7 MPa. Failures occurred on the order of 10⁵ to 10⁷ cycles, and an S-N curve was generated based off of the failure results. After the samples failed, the location of the failure and the number of cycles to failure were noted. Fatigue samples were designed in SolidWorks with a tapered 2 inch reduced section. The 2 inch reduced section will include the entire weld region as seen from the microhardness …

Relationship Between Bagging Methods And Pre-Weld Holding Times On Porosity Formation In 2219 Aluminum Ac-Tig Welds, Mariah Grace Head, Tyson Daniel Mobley

Materials Engineering

The purpose of this study was to determine relationships between bagging methods and pre-weld holding times on the formation of porosity when AC-TIG welding 2219 aluminum. Considering the strict guidelines and specifications required within the aerospace industry, maintaining quality welds is of paramount importance to control part integrity for aerospace applications. This project focused on two parameters involved in the preparation of aluminum parts for welding: bagging method and pre-weld holding time. Welding geometry was simplified to bead-on plate instead of the standard joint welds. Radiographic analysis of the samples showed that all levels of both parameters produced “passing welds.” …

An Intercritical Heat Treatment Study Of High Strength, Microalloyed Ferrous Open Die Forgings, Kelly Elizabeth Stewart

Materials Engineering

High strength, low alloy steel is most commonly utilized in plate or sheet form-with a thickness under 4 in, one unconventional application however, is open die forging where cross-sectional area can be as large as 9.5 in by 11.5 in. When forging to larger section size than one would thermo-mechanically roll sheet steel, a new set of complications, such as variation in microstructure and mechanical properties, arise. This study investigates the heat treatment and processing options needed to negate the inherent microstructural irregularity and Charpy V-Notch (CVN) toughness variation. Intercritical heat treatment—normalizing and then quench and tempering above the A …

Characterization Of Pressure Driven And Electro-Kinetically Driven Flow In A Micro-Fluidic Chip Using Particle Imaging Velocimetry, Alexis Paige Weckel

Materials Engineering

The goal of this research is to compare electro-kinetic and pressure driven flow rates and velocity profiles (near wall vs. middle) in a microfluidic chip made of PDMS using particle imaging velocimetry (PIV) of an aqueous solution of fluorescent polystyrene (PS) particles using a laser confocal microscope (LCM). Microfluidic channels were fabricated out of PDMS using a SU-8 mold to be 25mm long and 180um by 1000um. Pressure-driven data did not show the expected parabolic profile because of the large width to depth ratio. In addition, data showed a calculated average significantly higher than the projected particle velocity through the …

Mechanical Behavior Of Compression Molded Polyethylene Terephthalate, Daniel Cole Greinke, Paul Jackson Mcewan, Dan Tran

Materials Engineering

The purpose of this project was to investigate the effects of time, temperature, and pressure on the tensile strength and elastic modulus of recycled PET. Compression molding trials were performed on shredded PET bottles to produce tensile test specimens conforming to ASTM D638-03. Aluminum molds containing the PET were mechanically fastened together at the desired pressure and heated in an electric oven. The resulting specimens were subjected to tensile testing for analysis. This screening experiment failed to generate any statistically significant data concerning the factors of interest. These preliminary results may be used to design a more systematic follow-up study.