Sean R. Agnew
Research Interests
We are working to develop more quantitative connections between the microstructure and properties (primarily mechanical) of advanced crystalline materials through experimentation and modeling. The properties of most crystalline materials exhibit anisotropies characteristic of their crystal symmetry and "orientation related effects" ultimately impact materials performance in every modern industry.
As an example, elastic deformation behavior is affected by the presence of textures or other complex microstructures and we have a project which focuses on the interaction between elastic (ultrasonic) waves and microstructure. Presently, these interactions are viewed as deleterious for the nondestructive evaluation (NDE) of components (e.g. weldments or forgings.) We are investigating the possibility that quantitative assessments of the microstructure might be made in a nondestructive fashion.
Plastic deformation is particularly interesting in the context of textures since it is often responsible for the observed textures in the first place, and because it is subsequently affected by the presence of texture. Polycrystal plasticity modeling has been successfully employed to predict texture evolution and resultant anisotropy. Further, these models may be used to solve the inverse problem of identifying deformation mechanisms involving dislocation slip and/or mechanical twinning. Finally, thin films and coatings often exhibit strong textures due to preferred growth kinetics, or high internal/residual stresses.
Experimentally, we use a variety of diffraction-based tools to measure the orientation and stress-state of invdividual grains and polycrystals ranging from electron diffraction in an SEM (EBSD) or TEM, to x-ray diffraction in our home laboratory or at a synchrotron, to neutron diffraction at a reactor or pulsed neutron source. These structural measurements are linked to measurements of the mechanical properties measured using universal testing machines, formability tests, or ultrasonic testing. A favorite approach is to link mechanical behavior and characterization techniques through the use of in-situ testing where the material is characterized during deformation.
Research Scientists
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Jishnu J. Bhattacharrya
jjb4cp@virginia.edu
Education:
Ph.D. Material Science and Engineering, University of Virginia, 2016
M.Tech. Metallurgical Engineering, Indian Institute of Technology, Kharagpur, 2011
B.Tech. Metallurgical Engineering, National Institute of Technology, Durgapur, 2009
Graduate Students
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Nathan E. Peterson
np7ut@virginia.edu
Degree:
Ph.D. Student
Education:
M.S. Materials Science & Engineering, Michigan Technological University, 2018
B.S. Materials Science & Engineering, Michigan Technological University, 2016
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Mark A. Wischhusen
maw9ef@virginia.edu
Degree:
Ph.D. Student
Education:
B.S.E Chemical Engineering, University of South Carolina, 2017
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Michael A. Ritzo
mar3dm@virginia.edu
Degree:
Ph.D. Student
Education:
B.S. Chemical Engineering, University of Virginia, 2018
B.S. Engineering Science - Material Science & Engineering Concentration, University of Virginia, 2018
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Hunter S. Macdonald
hm5gy@virginia.edu
Degree:
Ph.D. Student
Education:
B.S. Mechanical Engineering, United States Military Academy, West Point NY, 2009
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Matt Szeto
mws8xv@virginia.edu
Degree:
Masters Student
Education:
B.S. Physics, Rochester Institute of Technology
Undergraduate Students
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Joshua Rigby
jr2bc@virginia.edu
Major:
Mechanical Engineering
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Vikaas S. Bajikar
vsb4tw@virginia.edu
Major:
Mechanical Engineering
Alumni
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Matthew Steiner
Degree/Date:
Postdoctoral Fellow /
Thesis/Research Topic:
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Employment:
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Md. Shamsujoha
Degree/Date:
Ph.D. Student /
Thesis/Research Topic:
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Employment:
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Fulin Wang
Degree/Date:
Ph.D. Student /
Thesis/Research Topic:
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Employment:
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Robert Klein
Degree/Date:
Masters Student /
Thesis/Research Topic:
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Employment:
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John Einhorn
Degree/Date:
Masters Student /
Thesis/Research Topic:
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Employment:
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Yuanqing Chi
Degree/Date:
Visiting Ph.D. Student /
Thesis/Research Topic:
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Employment:
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Chris A. Calhoun
Degree/Date:
Ph.D. / 2016
Thesis/Research Topic:
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Employment:
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Jasmine J. Keene
Degree/Date:
Masters of Science / 2013
Thesis/Research Topic:
Exploring Ni-bonded TiC for Cellular Materials
Employment:
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Peter Lekeaka-Takunju
Degree/Date:
Postdoctoral Research Associate / 2013
Thesis/Research Topic:
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Employment:
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Rupalee Mulay
Degree/Date:
Postdoctoral Research Associate / 2012
Thesis/Research Topic:
Understanding the Anomalous Ductility of Select B2 Intermetallic Alloys
Employment:
Materials and Process Engineering, Battelle India, Pune
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James Wollmershauser
Degree/Date:
Ph.D. / 2011
Thesis/Research Topic:
Using In-situ Neutron Diffraction to Understand the Elastoplastic Behavior of Complex Alloys
Employment:
Staff Scientist, Naval Research Laboratory, Washington, D.C.
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Jason Hadorn
Degree/Date:
Ph.D. / 2010
Thesis/Research Topic:
Mechanisms of texture weakening in magnesium rare earth element alloys
Employment:
Postdoc, Kumamoto University, Kumamoto, Japan; Postdoc, National Institute of Materials Science, Tsukuba, Japan
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Christopher Amaro
Degree/Date:
Masters of Science / 2010
Thesis/Research Topic:
Nonlinear ultrasonic characterization of fatigue damage and heat treatment of Aluminum Alloys
Employment:
Process Engineer, Firth Rixson, Savannah, Georgia Area
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F. John Polesak, III
Degree/Date:
Masters of Science / 2010
Thesis/Research Topic:
Constitutive behavior of magnesium rare earth alloys
Employment:
Product Development Engineer, Firth Rixson, Savannah, Georgia
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Babak Raeisinia
Degree/Date:
Postdoctoral Research Associate / 2010
Thesis/Research Topic:
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Employment:
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Vipul K. Gupta
Degree/Date:
Ph.D. / 2009
Thesis/Research Topic:
Diffraction-based Investigation of Crack Wake Plasticity in Aerospace Aluminum Alloys
Employment:
Postdoc, National Institute of Aerospace, Langley, Virginia
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C. John Neil
Degree/Date:
Masters of Engineering / 2008
Thesis/Research Topic:
Crystal Plasticity-Based Forming Limit Diagram Prediction
Employment:
Technical staff, Jefferson Theater, Charlottesville
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Achim Wendt
Degree/Date:
Vistor / 2008
Thesis/Research Topic:
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Employment:
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Jeremy W. Senn
Degree/Date:
Masters of Science / 2007
Thesis/Research Topic:
Recrystallization Texture Evolution of Magnesium Alloys Containing Rare Earth Elements
Employment:
Process Engineer, Neuman Aluminum Impact Extrusion Inc., Waynesboro, Virginia
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Marco Rodriguez
Degree/Date:
Vistor / 2007
Thesis/Research Topic:
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Employment:
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Kirsten Hantzsche
Degree/Date:
Vistor / 2007
Thesis/Research Topic:
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Employment:
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Ashutosh Jain
Degree/Date:
Masters of Science / 2005
Thesis/Research Topic:
Modeling the Role of Deformation Twinning in Mg Alloy AZ31B
Employment:
Senior Packaging Engineer, Intel, Tucson, Arizona
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Yun Jo Ro
Degree/Date:
Ph.D., M.S. / 2004
Thesis/Research Topic:
Characterization of Exposure Dependent Fatigue Crack Growth Kinetics and Damage Mechanisms for Aluminum Alloys (Ph.D.), Fatigue Crack Surface Crystallography of Precipitation Strengthened (M.S.)
Employment:
Postdoc, Max-Planck-Institut fur Eisenforschung, Dusseldorf; R&D staff member, POSCO (formerly Pohang Iron and Steel Company), Pohang, South Korea
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Özgür Duygulu
Degree/Date:
Masters of Science / 2004
Thesis/Research Topic:
Anisotropy and Deformation Mechanisms of Magnesium Alloys AZ31B Sheet
Employment:
R&D staff, Tubitak, The Scientific and Technological Research Council of Turkey, Ankara
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Fei Zeng
Degree/Date:
Masters of Science / 2004
Thesis/Research Topic:
Ultrasonic Chracterization of High Purity Niobium
Employment:
Structural Engineer, GMS, LLP, New York