Category: Seminars

Materials Characterization using Scattering Techniques

Monday, February 27, 2012 3:00 pm – 4:00 pm
Room 610, M&M Building

Heinz Nakotte
Gardiner Professor, Chair of the Engineering Physics Committee, Department of Physics, New Mexico State University
and
Instrument Scientist, Single Crystal Diffractometer (SCD), Los Alamos Neutron Science Center, Los Alamos National Laboratory

Abstract

In many cases, materials properties of interest for applications are determined by the structuralfeatures at atomic, nano and/or micron level. While diffraction typically only provides a measureof the volume-averaged structure of the material of interest, the local structure is accessiblethrough total-scattering studies in combination with pair-distribution function analysis. In mylecture, I intend to discuss and compare the opportunities and limitations of total-scatteringstudies using neutrons and synchroton X-rays. I will present some recent results of two of myresearch projects, i.e. local structure of a non-platinum catalyst and evidence for resonant unitmodes in a framework structure that exhibit negative-thermal-expansion behavior. If time permits,I will also provide a brief summary of my other research projects.


Mesoscale Anisotropic Deformation and Damage Nucleation In Polycrystalline Ti Alloy

Friday, February 24, 2012 3:00 pm – 4:00 pm
Room 610, M&M Building

M. A. Crimp
Chemical Engineering and Materials Science
Michigan State University, East Lansing, MI

Abstract

A combination of experimental characterization and crystal plasticity finite element modeling(CPFEM) has been used to study the anisotropic deformation of a number of titanium alloys.Studies have been carried out in the near surface region of 4-point bend specimens, where theglobal stress can be approximated as uniaxial tension.  Specific microstructural patches havebeen characterized prior to deformation using electron backscattered electron diffractionorientation imaging microscopy (OIM).  Specimens have been deformed both in-situ in scanningelectron microscopy (SEM) and ex-situ, facilitating a range of experimental characterizationmethods including optical microscopy, atomic force microscopy, SEM based backscatteredelectron imaging, OIM, and channeling contrast imaging, as well as 3-D X-ray diffraction.  Thesestudies have allowed a comprehensive experimental characterization of the nature of plasticdeformation and damage nucleation in the microstructural patches.  To complement thesestudies, quasi 3-D FEM meshes, developed based the experimentally characterizedmicrostructural patches, have been computationally deformed.  While the simulations accuratelyreproduce significant aspects of the experimental studies, including some crystal rotations andsurface topography development, further work to include grain boundary behavior in thesimulations is needed.

More information: Mesoscale Anisotropic Deformation and Damage Nucleation In Polycrystalline Ti Alloy


BaTiO3 Glass-Ceramics Composites For High Energy Storage Capacitors

Thursday, February 23 2012 2:00 p.m.
Room 610, M&M Building

Douglas B. Chrisey
Department of Material Science and Engineering, Department of Biomedical Engineering
Rensselaer Polytechnic Institute, Troy, NY, 12180

Abstract

Renewable energy sources require large-scale power storage so that their inherently intermittent supply of power can meet demand.  For capacitive energy to have the necessary high volumetric and gravimetric energy storage density this will require the dielectric layer to simultaneously possess a high dielectric constant and a high breakdown strength, e.g., in excess of 10,000 and 1 MV/cm, respectively.  To be a realistic solution for renewable energy storage, it must also be low cost and scalable, i.e., no roadblocks from the laboratory prototype to large scale production, and to achieve the all of the aforementioned requirements we have exploited a glass-ceramic phase.  It is expected that glass-ceramics composites will have higher breakdown strength than that of a sintered ceramic alone, because the glass would displace the air-filled voids.  Due to the dielectric mixing rule, the dielectric constant of the composite mixture will then be limited by the low permittivity of the glass phase in comparison to the ceramic phase.  In our work, we use a glass phase that can undergo a phase transformation into BaTiO3-precipitating glass-ceramic by controlled crystallization (annealing temperature).  The benefit of doing this is that we achieve a higher dielectric constant of composite mixture, due to the additional high dielectric constant BaTiO3 phase, while also improving the high breakdown strength. It was demonstrated that this BaTiO3-precipitaing glass-ceramic and BaTiO3 ceramic composite are promising for improved dielectric properties for high-density energy storage capacitors.


Design, Analysis, Testing, Filling and Sealing HIP Cans for the Calcine Disposition Project at the Idaho National Engineering Laboratory

Friday, February 3, 2012 11:00 am – 12:00 pm
Room 610, M&M Building

Dr. Delwin C. Mecham
CWI (Idaho National Engineering Laboratory)

Abstract

The Calcine Disposition Project (CDP) of the Idaho Cleanup Project (ICP) hasthe responsibility to retrieve, treat, and dispose of the calcine stored at theIdaho Nuclear Technology and Engineering Center (INTEC) located at theIdaho National Laboratory in Southeast Idaho.  Calcine is the product ofthermally treating, or “calcining”, liquid high-level or sodium-bearing nuclearwaste produced at INTEC from 1963 to 1998 during the reprocessing of spentnuclear fuel (SNF).  The CDP is currently completing the design of the HotIsostatic Pressure (HIP) treatment process for the calcine to produce a volumereduced, monolithic, glass-ceramic waste form suitable for transport anddisposition.Conceptual design for the CDP requires the design of a large scale HIP canwhich maintains containment of calcine during the HIP treatment cycle. The HIPcan must be filled with calcine and additives and sealed remotely. The HIP cans will undergo approximately 50%volume reduction at a temperature of 1000-1250°C and a pressure of 50-100MPa.  The HIP can’s main function isto provide primary containment of the radioactive calcine material during and after the HIP treatment process.Development of a virtual testing program using high fidelity modeling techniques is required due to the prohibitivecost of full-scale testing using actual HLW calcine.This presentation will  describe current design, analysis, and testing of HIP cans and the design for filling andsealing HIP Cans.  The basic HIP technology is summarized and the remote HIP can fill and seal design ispresented.  Simulation models are developed to establish a virtual testing program using Finite Element Analysis(FEA).   Software packages COMSOL and ABAQUS are being used to analyze the thermal and structural responseof HIP cans during the HIPing process.  The software packages increase the understanding of can deformation andallow for virtual testing before large scale testing of the HIP cans.  This decreases the number of physical HIP cantests needed during the development of a HIP can design.  The models utilize a macroscopic representation of thegranular material “constitutive model” for the material inside the can and a non-linear representation of the stainlesssteel. Initial small scale testing of HIP cans has been performed to benchmark the FEA analysis and providevalidation of the constitutive models used.  Analytic results, test data, and comparisons between them are presented.

Biography

Dr. Del Mecham has forty years of experience in the planning and management of large-scale thermal-hydraulicexperiments including the development and application of thermal-hydraulic computer codes for nuclear reactor safety analysis.Dr. Mecham has developed and managed irradiation testing programs and has participated on national and internationalresearch technical advisory boards.  Del received his PhD in Mechanical Engineering from Utah State University and is aRegistered Professional Engineer in the State of Idaho.  Dr. Mecham serves on the Industrial Advisory Committee forMechanical Engineering at Utah State and holds an Adjunct Professor position at the University of Idaho.


Design, Analysis, Testing, Filling and Sealing HIP Cans for the Calcine Disposition Project at the Idaho National Engineering Laboratory

Thursday, December 15, 2011 11:00 am – 12:00 pm
Room 610, M&M Building

Dr. Delwin C. Mecham
CWI (Idaho National Engineering Laboratory)

Abstract

The Calcine Disposition Project (CDP) of the Idaho Cleanup Project (ICP) has the responsibility to retrieve, treat, and dispose of the calcine stored at the Idaho Nuclear Technology and Engineering Center (INTEC) located at the Idaho National Laboratory in Southeast Idaho. Calcine is the product of thermally treating, or “calcining”, liquid high-level or sodium-bearing nuclear waste produced at INTEC from 1963 to 1998 during the reprocessing of spent nuclear fuel (SNF). The CDP is currently completing the design of the Hot Isostatic Pressure (HIP) treatment process for the calcine to produce a volume- reduced, monolithic, glass-ceramic waste form suitable for transport and disposition.
Conceptual design for the CDP requires the design of a large scale HIP can
which maintains containment of calcine during the HIP treatment cycle. The HIP can must be filled with calcine and additives and sealed remotely. The HIP cans will undergo approximately 50% volume reduction at a temperature of 1000-1250°C and a pressure of 50-100MPa. The HIP can’s main function is to provide primary containment of the radioactive calcine material during and after the HIP treatment process. Development of a virtual testing program using high fidelity modeling techniques is required due to the prohibitive
cost of full-scale testing using actual HLW calcine. This paper describes current design, analysis, and testing of HIP cans and the design for filling and sealing HIP Cans. The basic HIP technology is summarized and the remote HIP can fill and seal design is presented. Simulation models are developed to establish a virtual testing program using Finite Element Analysis (FEA). Software packages COMSOL and ABAQUS are being used to analyze the thermal and structural response of HIP cans during the HIPing process. The software packages increase the understanding of can deformation and allow for HIP can virtual testing before large scale testing of the HIP cans. This decreases the number of physical HIP can tests needed during the development of a HIP can design. The models utilize a macroscopic representation of the granular material “constitutive model” for the material inside the can and a non-linear representation of the stainless steel. Initial small scale testing of HIP cans has been performed to benchmark the FEA analysis and provide validation of the constitutive models used. Analytic results, test data, and comparisons between them are presented.

Biography

Dr. Del Mecham has forty years of experience in the development and application of thermal-hydraulic computer codes for nuclear reactor safety analysis; planning and management of large-scale thermal-hydraulic experiments. Dr. Mecham has developed and managed irradiation testing programs as well as participated on national and international research technical advisory boards; program development and technical management. Dr. received his PhD in Mechanical Engineering from Utah State University and is a Registered Professional Engineer in the State of Idaho. Dr. Mecham serves in the Industrial Advisory Committee for Mechanical Engineering at Utah State and holds an Adjunct Professor position at the University of Idaho.


Hydrogen Storage in Complex Metal Hydrides and Metal Organic Framework Materials: Challenges and Opportunities

Monday, November 14, 2011 10:00 am – 11:00 am
Room 610, M&M Building

Yves J. Chabal
Department of Materials Science and Engineering University of Texas at Dallas

Abstract

The hydrogen economy critically depends on the ability to store hydrogen safely with high gravimetric and volumetric capacities. Three approaches are being seriously considered by DOE at present: 1) chemical hydrides, 2) complex metal hydrides, and 3) microporous materials. Each approach faces fundamental issues that will require scientific breakthroughs to incorporate them into practical systems. In our group, we are studying two different systems (#2 and 3) and addressing the following fundamental questions: 1) how can hydrogen dissociate on aluminum and what is the nature of mass transport in complex alanates to form complex metal hydrides? and 2) What is the nature of interactions for H2 molecules in microporous metal organic framework (MOF) materials?
To address these questions, we bring to bear a number of characterization methods, such as infrared (IR) absorption spectroscopy, Raman scattering, mass spectrometry, and isotherm measurements. With the help of first principles calculations performed by our collaborators, we derive detailed information on the interaction, dissociation, and product formation for hydrogen on aluminum
surfaces. On aluminum surfaces, the primary objective is to identify the formation of alanes and understand their formation, as well as to understand the role of catalysts such as titanium in dissociation and kinetics of hydrogen. In microporous MOF materials, our primary objectives are to better understand and explain molecule-sorbent interactions within these systems and to provide insight and guidelines toward the design, synthesis and modification of MOF structures for enhanced molecular adsorption strengths, storage capacity and selectivity. Beyond the study of existing and new MOFs, this program is intended to develop novel experimental and theoretical methods to advance the understanding of molecular incorporation into a broader class of microporous materials, to predict improved materials with active metal centers, and to direct the optimized synthesis processes for a variety of applications (storage, separation, sensors).
Work supported by DOE-BES.

Biography

Yves Chabal holds a Texas Instrument Distinguished Chair in Nanoelectronics at the University of Texas at Dallas. He obtained a BA in Physics from Princeton University in 1974, and a Ph.D. in Physics from Cornell University in 1980. He then joined Bell Laboratories where he developed sensitive spectroscopic methods to characterize surfaces and interfaces. He worked at Murray Hill, New Jersey, from 1980 until 2002 for AT&T, Lucent Technologies (1996) and Agere Systems (2001) in the Surface Physics, Optical Physics and Materials Science departments. In 2003, he joined Rutgers University as Professor in Chemistry and Biomedical Engineering, where he expanded his research into new methods of film growth (atomic layer deposition), bio- sensors, and energy (hydrogen storage). He directed the Laboratory for Surface Modification, an interdisciplinary
Center to promote large initiatives. He joined UT Dallas in January 2008 to lead the Materials Science and Engineering department in the Erik Jonsson Engineering School.
He is a Fellow of the American Physical Society and the American Vacuum Society, received a Bell Laboratories Affirmative Action Award (1994), an IBM faculty award (2003), the Rutgers Board of Trustees Award for Excellence in Research (2006), and the Davisson-Germer Prize (2009), the Tech Titan Technology Innovator Award in 2010, and has recently been recognized by the ACS for encouraging women into careers in the Chemical Sciences.


Understanding Segregation Defect Formation in Remelting Processing of High Temperature Alloys

Friday, October 21, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Matthew John M. Krane
Associate Professor of Materials Engineering Purdue Center for Metal Casting Research Purdue University, West Lafayette, Indiana

Abstract

Remelting processes provide routes to large ingots of specialty metals which have relatively few defects. However, past certain limits on size of the ingots and speed of these processes several types of segregation related defects begin to occur. The heat, mass and momentum transfer and electromagnetics present during electroslag and vacuum arc remelting (ESR and VAR) are modeled and sump profiles and macrosegregation patterns are predicted. These results are studied as functions of process parameters and ingot geometry. During ESR of nickel-based superalloys, a maximum in macrosegregation is found as a function of filling velocity in the flow regime dominated by buoyancy. During VAR of titanium alloys, DC current levels are generally much higher than the AC current in ESR, so the sump flow is controlled by Lorenz forces, leading to different segregation patterns. The numerical simulations include studies of two distinctive flow regimes in VAR: strong counter-clockwise Lorentz driven flow and weak clockwise buoyancy driven flow. The results demonstrate possible influence of process instabilities and the electrode composition on the flow regime and thus macrosegregation. The practice of multiple VAR melts is also simulated, showing the effects of each step on the final solute distribution. Experimental validation of the models and other current projects on remelting processes will also be discussed.

Biography

Dr. Matthew Krane is an Associate Professor of Materials Engineering at Purdue University and a member of the Purdue Center for Metal Casting Research. His research is on design, development, and modeling of materials processes, particularly the solidification of metal alloys. He holds a Ph.D. (1996) from Purdue University in Mechanical Engineering, with a concentration on heat transfer and fluid flow in materials processing. His M.S. (1989) is from the University of Pennsylvania and his B.S. (1986) from Cornell University, both in mechanical engineering. In addition to consulting with the metals processing industry, he also worked for three years (1988-1991) on thermal packaging and manufacturing issues for Digital Equipment Corporation in Andover, Massachusetts. In 2006, he was a Visiting Research Fellow working in the Interdisciplinary Research Centre at the University of Birmingham (UK) and was granted a courtesy appointment in Purdue’s School of Mechanical Engineering in 2008. Serving on several technical committees in the ASME and TMS, including holding the chair of the TMS Process Modeling and Control (2001-2003) and Solidification (2009-2011) Committees, he has organized or co-organized several symposia in his areas of research, including the Tenth International Conference on Modeling of Casting, Welding and Advanced Solidification Processes (MCWASP X) in 2003 and the Liquid Metal Processing and Casting Conference (LMPC) in Nancy, France in 2011. He is on the international technical committees for the MCWASP and the LMPC conference series. Professor Krane’s teaching experience includes heat transfer, fluid mechanics, engineering design, materials processing, numerical modeling, and ethics in engineering practice.


Ultrafine Grained Ti-6Al-4V for Aerospace Applications

Friday, September 30, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Dr. Judson S. Marte
General Electric Global Research Center Niskayuna, NY

Abstract

Improving the performance and reducing the cost of titanium components is important for aerospace applications, such as gas turbine engines. This presentation will provide an overview of an ongoing collaborative program between ATI Allvac and GE evaluating the production, characterization, and application of ultrafine-grained titanium. Multi-axis forging (MAF) has been used to produce bulk samples with submicron alpha grain size. Extensive characterization of the microstructure shows that, after MAF, the beta phase tends to pin alpha, enhancing thermal stability. Deformation properties have been evaluated and used to make finite element models of near-net shape forging processes. Laboratory-scale near-net shape forgings have been produced to demonstrate feasibility and provide material for microstructural and mechanical evaluation. Tensile and fatigue performance of the sub-scale forgings will be presented, as will a brief discussion of the challenges associated with developing a full-scale forging process.

Biography

Jud is currently the Manager of the Metals Processing and Testing Laboratory at GE Global Research in Niskayuna, NY. He is also a project leader and metallurgist who specializes in the thermomechanical processing of structural metals, low temperature superconductors, and magnetic materials. Prior to joining GE in 1999, he earned his PhD in Materials Science and Engineering at Virginia Tech studying the synthesis and processing of titanium- and titanium aluminide- matrix composites.