Category: Seminars

An Overview of Metallurgical Failure Analysis

Friday, September 23, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Joel F. Flumerfelt, PhD
Metallurgist Aspen Research Corporation, St. Paul, MN

Abstract

Materials have been used throughout history for various applications, for example, tools, weapons, buildings, vehicles and ornamentation. Invariably, components used within these products sometimes fail during service before their expected end of life. The past three decades have seen extreme failures that caused human fatalities, for example, the Space Shuttle Challenger explosion shortly after lift-off in 1986, the Space Shuttle Columbia explosion upon re- entry in 2003, and collapse of the Interstate 35W Mississippi River Bridge in Minneapolis, Minnesota, in 2007. When failure happens, there is usually a mandate to identify factors that contributed to the failure to make plans for avoiding failure in the future, i.e. design and build a better mouse trap. A failure analysis investigation satisfies the demand such that the work effort identifies: the failure mode; the immediate primary cause(s) for the failure; the root cause(s) for the failure associated with intentional and unintentional human errors. This presentation will illustrate the principles of the failure analysis process using a recent failure investigation related to a socket head cap screw that failed inside a shaker table.

Biography

Joel is a metallurgist who began his career at Aspen Research Corporation in 2000. As an analyst, he participates in various short term projects that address client inquiries related to failure analysis, foreign residue and deposit identification, microscopic examinations, mechanical testing, customized test method development, material selection and design, material and product quality control measures, and product process development and improvement. As a project manager, he interacts with Aspen’s clients to understand and respond to questions about material and process issues associated with their products, providing customized quotes that define a project’s objective, scope of work, cost, and timeline. He also oversees the operation and maintenance of the metallurgical lab, optical microscopes and SEM-EDS instrumentation.
Prior to joining Aspen Research Corporation, he spent 18 months at Engel Metallurgical, Ltd. (St. Cloud, MN) working on projects related to metallurgical failure analysis and material selection and design.
Joel holds a Bachelor of Science and Master of Science degree in Metallurgical Engineering from Michigan Technological University, and a Doctorate degree in Metallurgical Engineering from Iowa State University. He is a current member of ASM International and SMTA. A hobby of his is playing alto sax with a 17 person swing band, named “Red Rock Swing Band”, which performs at different locales around the Twin City metropolitan area for private and public gigs.


Ab Initio Investigation and Thermodynamic Modeling of Shape Memory Alloys

Friday, September 9, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Arpita Chari, Navdeep Singh Department of Mechanical Engineering, Texas A&M University

Abstract

Shape Memory Alloys are an interesting class of active materials that undergo reversible shape changes through martensitic transformations that can be triggered by temperature, stress and/or magnetic fields (in the case of ferromagnetic SMAs). Among recently investigated SMAs, Co2NiGa and Co2NiAl alloys have been receiving considerable interest due to their shape memory (SM) properties. While there have been many investigations on the mechanical and magnetic behavior of these materials, very little is known about the fundamental microscopic basis for the observed macroscopic behavior.
In the first part of the talk, we discuss the stability of Co2NiGa and Co2NiAl-based structures. The transformation of the cubic austenite to the tetragonal martensite structure is investigated through Bain distortion paths as well as lattice dynamical calculations. Analysis of the features of the electronic structure are then mapped to the observed metastability of the cubic phases with respect to tetragonal deformations and comparisons are made with the much more studied Ni2MnGa-based SMAs. We also investigate the magnetic behavior of these alloys by using Monte Carlo simulations in combination with ab initio methods.
In the second part of the talk we will focus on the use of the first-principles calculations in combination with experimental information to develop accurate thermodynamic models —based on the CALPHAD approach—for the Co-Ni-Ga ternary system. These thermodynamic models are then used to predict phase constitution as a function of alloy composition and temperature. Reliable thermodynamic models can be used in the computer-aided design of novel shape memory alloys based on this ternary system.

Biography

Dr. Arroyave got his B. S. in Mechanical and Electrical Engineering at ITESM (Monterrey, Mexico). Afterwards, he enrolled at the Massachusetts Institute of Tecnoloogy, where he got his M. S. (2000) and Ph.D. (2004) in Materials Science and Engineering under the supervision of Prof. Thomas W. Eagar. After two and a half years as a Postdoctoral Scholar in Prof. Zi-Kui Liu’s group at Penn State he joined the faculty of Mechanical Engineering and Materials Science at Texas A&M University in 2006. Dr. Arroyave’s expertise is in computational thermodynamics and kinetics of materials (using the CALPHAD method), phase-field methods and use of electronic structure methods to predict the structural/functional properties of materials at the atomic scale. Dr. Arroyave’s group is also working with experimental colleagues to develop Integrated Computational Materials Engineering (ICME) approaches to optimize complex multi-phase, multi-component structural alloys.


The Future of Automotive Propulsion: One Perspective

Thursday, September 1, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Dr. Edward P. Becker
Materials Technical Specialist General Motors, LLC

Abstract

The worldwide demand for automotive transportation remains strong even as the price of conventional fuels rises. General Motors is committed to providing safe and affordable vehicles which run on whatever fuel is available in a particular market. To assist in extending the current supply of fossil fuels, automakers (including GM) are expanding the use of fuel-saving technologies such as variable valve actuation, cylinder deactivation, additional forward-speed transmissions, and hybrid powertrains. In addition, vehicles which run on Compressed Natural Gas (CNG) and alcohol-gasoline blends (such as E85) are commercially available. GM has also demonstrated a hydrogen fueled, internal combustion engine vehicle and is aggressively pursuing fuel cells for automotive transportation in the future.

Biography

Ed Becker is a Technical Specialist in the Materials Engineering Department at General Motors Powertrain in Pontiac, Michigan. His responsibilities include initiating and managing research and development activities related to innovative materials and processes for GM engines and transmissions. Ed Becker is Past President and a Fellow of the Society of Tribologists and Lubrication Engineers. He has worked for General Motors for over 28 years, mostly in the Powertrain division working on a variety of GM engines and transmissions. He is a licensed Professional Engineer in Michigan.
Ph.D. and M.S., Mechanical Engineering, University of Michigan M.S, Metallurgical Engineering, University of Illinois B.S., Metallurgical Engineering, Illinois Institute of Technology


Nanoporous Materials for Energy and Environmental Application

Friday, May 6, 2011 10:00 am – 11:00 am
Room 610, M&M Building

Prof. Randall Q. Snurr
Department of Chemical & Biological Engineering
Northwestern University, Evanston, IL

Abstract

Metal-organic frameworks (MOFs) are a new class of nanoporous materials synthesized
in a “building-block” approach by self-assembly of metal or metal-oxide vertices
interconnected by rigid organic linker molecules. The rational synthesis approach opens
up the possibility of incorporating a wide variety of functional groups into the materials,
and these materials may lead to new advances in adsorption separations, gas storage,
sensing, and catalysis. Some of the most intensively studied applications are related to
solving energy and environmental problems, including hydrogen storage for fuel cell
vehicles, capture of CO2 from power plant exhaust, and energy efficient separations.
Because of the predictability of the synthetic routes and the nearly infinite number of
variations possible, molecular modeling is an attractive tool for screening new structures
before they are synthesized. Modeling can also provide insight into the molecular-level
details that lead to observed macroscopic properties. This talk will provide an overview
of MOFs and their potential applications, as well as efforts to predict their properties
using molecular modeling.

Biography

Randy Snurr is a Professor of Chemical and Biological Engineering at Northwestern University. He holds BSE and PhD degrees in chemical engineering from the University of Pennsylvania and the University of California, Berkeley, respectively. From 1994-95, he performed post-doctoral research at the University of Leipzig in Germany supported by a fellowship from the Alexander von Humboldt Foundation. Other honors include a CAREER award from the National Science Foundation and the Leibniz professorship at the University of Leipzig in 2009. He is a Senior Editor of the Journal of Physical Chemistry and has served on the editorial boards of the Journal of Molecular Catalysis A, Catalysis Communications, and Current Nanoscience. His research interests include development of new nanoporous materials for energy and environmental applications, molecular simulation, adsorption separations, diffusion in nanoporous materials, and catalysis.


The Main Types of Gasar Structure and Production Methods

Monday, April 18, 2011 1:00 pm – 2:00 pm
Room 610, M&M Building

Dr. Vladimir Shapovalov
Department of Materials Science
National Metallurgical Academy of Ukraine

Abstract

This presentation will present a broad classification of gas-eutectic material (gasars) structures, based on experimental data obtained in former USSR, Russia, Ukraine, China, Japan and USA from 1979 to the present time. The presentation will also review gasar production methods and designs of gasar devices for laboratory and industrial manufacturing.

Biography

Dr. Shapovalov is an adjunct professor at the National Metallurgical Academy of Ukraine and seniorresearcher at Materials and Electrochemical Research Corporation of Tuscon, Arizona.  He graduated with a PhDfrom the National Metallurgical Academy of Ukraine in 1972 and has since worked there as a lecturer and professorof Materials Science.  From 1997-2000 he was project manager at Sandia National Laboratory in charge of Gasarmetallic foam research.  He has authored numerous papers on hydrogen equilibrium and advanced materialsprocessing with an emphasis on metallic foam.  His current research interests include advanced plasma processingof Gasar foams for coatings.


Piezoelectricity and Flexoelectricity in Solid and Soft Materials

Friday, March 25, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Dr. John Y. Fu
Department of Mechanical and Aerospace Engineering
State University of New York

Abstract

Historically, the study of flexoelectricity is closely related to that of piezoelectricity though the physicalmechanisms behind these phenomena are completely different [1]. In solid dielectrics, bothpiezoelectricity and flexoelectricity can be derived from the energy coupling in crystalline structures,which are based on equilibrium thermodynamics. However, those phenomena in polymers and liquidcrystals are more complicated due to their complex molecular chains and conformations. Recently, agiant flexoelectric phenomenon has been observed in bent-core nematic liquid crystal elastomers(BCLCEs) [2], which attracts much scientific attention since the nematic phase cannot be regarded asthe ferroelectric phase in most mesomorphic materials. It was believed that the giant flexoelectric effectmight only be observed in certain mesomorphic materials with the chiral smectic C* phase, a ferroelectricphase predicted by Meyer in the 1970s for liquid crystals [3]. Inspired by this study, we investigatedcertain polyvinylidene fluoride (PVDF) polymer films. A giant flexoelectric effect in a PVDF polymer filmwith mixed α- and β-phases has been observed in our group [4], which contradicts the previoustheoretical estimation that the flexoelectric coupling is small, on the order of 10 pC/m. In this seminar, Iwill re-visit the definitions of both piezoelectricity and flexoelectricity in solid dielectrics, and then comparethem with their counterparts in liquid crystals and polymers. Some peculiar physical phenomena relatedto both piezoelectricity and flexoelectricity in polymers will also be discussed. Finally, I will demonstratethat such a giant flexoelectric effect can be exploited to fabricate soft flexoelectric piezoelectriccomposites and devices by using non-piezoelectric soft materials.

References: [1] P. G. de Gennes, Physics of Liquid Crystals (Oxford University Press, London, 1974). [2] J. Hardenet al., Appl. Phys. Lett. 96, 102907 (2010). [3] R. B. Meyer, L. Liebert, L. Strzelecki, P. Keller, J. Phys. Lett. (Paris)36, 69 (1975). [4] J. Y. Fu et al., “Giant flexoelectricity in a polyvinylidene fluoride film”, submitted to Applied PhysicsLetters.

Biography

Dr. John Y. Fu is an assistant professor of mechanical engineering. He came to Buffalo and joined theMAE Department in August 2008. Between 2005 and 2008, Dr. Fu worked as a postdoctoral scholar in a navysponsored materials research laboratory. He completed his college education in China, and received his Ph.D.degree in electrical engineering from the Pennsylvania State University at University Park in December 2004. Dr.Fu holds one American patent and four American and international pending patents. His current research interestsfocus on polymer physics, dielectric polymers, ferroelectric polymers, liquid crystal polymers, flexoelectricpiezoelectric polymer composites and devices, and flexoelectric and flexoviscous phenomena in polymers andbiomaterials.


The Pressure Dependence of Pore Morphology in Aluminum Gasarite Metallic Foams Produced by Thermal Decomposition

Friday, March 18, 2011 3:00 pm – 3:30 pm
Room 610, M&M Building

Joe Licavoli
Graduate Student
Materials Science and Engineering
Michigan Technological University

Abstract

Gasarite metallic foams are those in which porosity is elongated due to eithergas-metal eutectic growth or evolution of gas from particulate during chillcasting.  Gasarite foams have several superior properties compared to othermetallic foam types, but in general repeatability of experimental results is amajor issue when studying such systems.  The current study replicatesexperiments conducted by other research groups in which ambient pressurewas varied during chill casting of pure aluminum on titanium hydride.According to ideal gas behavior it is expected that decreasing pressure at aconstant temperature will increase pore size and thus porosity, howeverquasi-boiling conditions and subsequent escape of gases from thesolidification front may nullify this effect.  Additional information provided inthis study includes the velocity profile of the solidification front, vacuumlevels, titanium hydride particle size, microstructure around pores andpackaging of the particulate are reported.  In agreement with previousstudies, it was found that operating under vacuum conditions increasesporosity and the tendency to form columnar pores.  Disagreement has beenfound in the propensity to form pores more than 10mm in length and inuniformity of pore radii.  Potential reasons for this disagreement have beendeduced from micro and macrostructural information.  Further studies andintegration of results into process models will be discussed.


Design and Application of Bioadhesives Inspired by Marine Mussels

Friday, March 4, 2011 3:30 pm – 4:30 pm
Room G05, Rekhi Hall

Bruce P. Lee
Director of New Technology
Nerites Corporation, Madison, WI

Abstract

Bioadhesives have a wide range of important applications in the biomedical field.  Tissueadhesives simplify complex surgical procedures to achieve effective wound closure and surgicalrepair. Despite these important functions, currently available adhesives seldom meet the basicrequirements for in vivo applications because of possible disease transmission, poor adhesivequality, or toxicity concerns. Thus, there is an ongoing need for the development of tissueadhesives with improved characteristics. Nature provides many outstanding examples ofadhesive strategies from which chemists and materials scientists can draw inspiration in theirpursuit of new biomaterials. Of particular interest is the mussel adhesive protein (MAP) secretedby marine mussels. MAP is initially secreted as a proteinaceous fluid, and then subsequentlyharden in situ to form an adhesive plaque, which allow mussels to bind tenaciously to varioustypes of surfaces underwater. One of the unique structural features of MAP is the presence of L-3,4-dihydroxyphenylalanine (DOPA), an amino acid post-translationally modified from tyrosine,which is believed to fulfill the dual role as the adhesive moiety and the crosslinking precursor.Our research focuses on the incorporation of DOPA and its derivatives in creating syntheticmimics of MAPs for various medical applications. In this seminar, I will discuss the design andapplication of these biomimetic adhesive materials.


Hybrid Nanomaterials and New Designs for Energy Conversion and Storage Applications

Friday, February 25, 2011 3:30 pm – 4:30 pm
Room G05, Rekhi Hall

Leela Mohana Reddy Arava
Postdoctoral Research Fellow, Department of Mechanical Engineering and Materials Science
Rice University

Abstract

In response to the needs of modern society and emerging ecological concerns, it is nowessential to provide efficient, low-cost, and environmentally friendly electrochemicalenergy conversion and storage devices. These electrochemical devices are expected tohave pronounced technological impact on the society – especially for powering anincreasingly diverse range of portable electronic and vehicular applications.Rechargeable Lithium-ion batteries and Fuel cells are amongst the most promisingcandidates in terms of their wide spread applicability, owing to their high energy andpower densities. The performance of these devices depends intimately on the propertiesof materials used to build them. This talk will focus on the new designs and performanceof the next generation of energy and power delivery devices by the use of tailorednanostructured materials and by nanoscale engineering. Some of the current challengespertaining to the energy storage technology and the effective utilization of new electrodematerials such as graphene and carbon nanotubes will be discussed. Furthermore, thetalk will also evaluate approaches for optimization of the Li-ion battery performance withnovel designs, leading to prototype nanoscale 3D battery architectures offeringimprovements in energy and power density with respect to the geometrical foot print ofdevices.


Bottom-Up Novel Hybrid Nanostructures for Solar Energy Harvesting

Monday, February 21, 2011 3:30 pm – 4:30 pm
Room G05, Rekhi Hall

Shenqiang Ren
Department of Materials Science and Engineering
Massachusetts Institute of Technology

Abstract

Nanostructured materials – including atomic clusters, quantum dots, nanowires or nanotubes –have dimensions in the range of 1 to 100 nm, the length scale that offers unique and sizetunable properties. They provide solutions to some of the current challenges in science andengineering, and would potentially lead to discoveries of new phenomena and novelapplications that are impossible to realize with their bulk counterparts. A challenging task in thisarea is to manipulate nanostructured materials and assemble them into desired structural forms– one, two or three-dimensional structures – so that their unique physical properties can beharvested. Among the bottom-up strategies, self-assembly of nanostructured materials andorganic conjugated polymers provides a promising route to the build-up of complex systems withimmense flexibility in terms of nanoscale building blocks and resulting novel physical properties.Current research is focused mainly on nanostructured hybrid solar cells that combine thebenefits of inorganic materials (thermal and chemical stability, high charge transport, solutionprocessing) and organic materials (strongly absorbing, mechanical flexibility, low-cost).

In this talk, I will discuss my research on rational design of self-assembling nanostructuredphotovoltaic systems on scales from molecular through macroscopic, to the development of“synthetic” strategies. Specifically, I will focus on three main topics: (a) bridging quantum dotsand conjugated polymer nanowires for efficient (>4%) hybrid solar cells; the data provides aunique new insight into the operation of hybrid bulk heterojunction devices and providesdirections to further improvements; (b) drying mediated self-assembly of inorganic nanowirehybrid solar cell; prospects for further enhancement will be discussed; (c) self-assembly of allconjugated block copolymers combined with metal oxide. The key aim of this study is to developa better understanding of the parameters that control such interfacial charge transfer processes.Another critical aim of this work is to develop quantitative structure-function relationships thatcan be used to guide the design and development of efficient nanostructured organic-inorganichybrid solar cells