Department of Materials Science and Engineering

Ralph E. Napolitano

Associate Professor
Iowa State University
Materials Science and Engineering
2220X Hoover Hall / 116 Wilhelm Hall
Ames, Iowa 50011-2300
Phone: 515-294-9101 / 515-294-1140
Fax: 515-294-5444
ralphn@iastate.edu




Link to Research Group Page

Education

  • B.S., Materials Science and Engineering,University of Florida, 1989
  • M.S., Metallurgical Engineering, Georgia Institute of Technology, 1994
  • Ph.D., Metallurgy, Georgia Institute of Technology, 1996

Academic Experience

  • Associate Professor, Department of Materials Science and Engineering
    Iowa State University, Ames, Iowa, 2005-present.
  • Scientist, Materials & Engineering Physics Program
    Ames Laboratory, U.S. Department of Energy Ames, Iowa, 1998-2005
  • Assistant Professor, Department of Materials Science and Engineering
    Iowa State University, Ames, Iowa, 2000-2005.
  • Associate Scientist and Solidification Science Coordinator, Materials & Engineering Physics Program
    Ames Laboratory, U.S. Department of Energy Ames, Iowa, 1998-2005
  • NRC Postdoctoral Fellow, Metallurgy Division, Materials Science and Engineering Laboratory
    National Institute of Standards and Technology, Gaithersburg, Maryland, 1997-1998.

Research Interests

  • Crystal-melt interfacial phenomena
  • Solidification dynamics
  • Microstructural modeling and simulation
  • Diffusive phase transformations
  • Multicomponent thermodynamics
  • Rapid solidification and metallic glass formation
  • Computational Materials Science

Research Description

    Ralph Napolitano's research group is focused on understanding the dynamic processes of morphological evolution during solid-liquid phase transformations in terms of the fundamental thermodynamic and kinetic properties of the crystal-melt interface and its local response to thermal, solutal, and structural fluctuations. Efforts involve experimental and theoretical investigations of crystal-melt interfaces under equilibrium, near equilibrium, and far from equilibrium conditions. Thermodynamic and kinetic properties that ultimately govern the dynamics of morphological transitions are investigated over all relevant length and time scales.

    Link to Research Group Page

Teaching

  • MatE 212 - Thermodynamics in Materials Engineering
  • MatE 341 - Metals Processing
  • MatE 443 - Ferrous Metallurgy
  • MatE 214 - Structural Characterization of Materials, Iowa State University
  • MSE 603 - Advanced Mathematics for Materials Science

Publications

  • S.H. Zhou and R.E. Napolitano, “Modeling of thermodynamic properties and phase equilibria for the Al-Sm binary system, J. Phase Equil. Diff., (in review) 2007.

  • Y. Yao, R.E. Napolitano, C.Z. Wang, and K.M. Ho, “Thermodynamic limits of crystallization and the prediction of glass formation tendency”, Scripta Mat (in review) 2006.

  • S.H. Zhou and R.E. Napolitano, “The stability of Al11Sm3 compounds, Met. Mat. Trans. (accepted, in press) 2006.

  • Y.E. Kalay, L.S. Chumbley, I.E. Anderson, R.E. Napolitano, “Characterization of Hypereutectic Al-Si powders solidified under far fro equilibrium conditions”, Met. Mat. Trans. (accepted, in press) 2006.

  • S.H. Zhou and R.E. Napolitano, “Thermodynamic properties of low-temperature Cu-Mg liquid and constrained equilibria involving an undercooled melt, J. Phase Equil. Diff. (accepted, in press) 2006.

  • S. Zhou, Y. Wang, F.G. Shi, F. Sommer, L.Q. Chen, Z.K. Liu, and R.E. Napolitano, “Thermodynamic assessment and modeling of phase equilibria for the Cu-Mg binary system”, J. Phase Equil. Diff. (accepted, in press) 2006.

  • R.E. Napolitano and J.R. Morris, “Frontiers in Solidification Science: Preface to the special issue”, Phil. Mag. 86 (2006) 3647-3649.

  • H. Meco and R.E. Napolitano, “Nonequilibrium chemical partitioning and phase formation in rapidly solidified Al-Sm and Ag-Sm binary alloys”, Mat. Sci. Forum 539-543 (2007) 2810-2815.

  • S. Zhou and R.E. Napolitano, “Phase equilibria and thermodynamic limits for partitionless crystallization in the Al-La binary system, Acta Materialia 54 (2006) 831-840. (pdf)

  • H. Meco and R.E. Napolitano, "Liquidus and solidus boundaries in the vicinity of order-disorder transitions in the Fe-Si system," Scripta Mat. 52 (2005) 221-226. <ahref="http://www.mse.iastate.edu/solidification/papers/ScriptaMat05.pdf" rtekeep="1">(pdf)

  • R. E. Napolitano and S. Liu, "The 3D crystal-melt Wulff-shape and interfacial stiffness in Al-Sn", Phys.Rev.B 70 (2004) 214103. (pdf)

  • J.J. Hoyt, M. Asta, T. Haxhimali, A. Karma, R.E. Napolitano, R. Trivedi, B. Laird, and J.R. Morris, "Crystal-melt interfaces and solidification morphologies in metals and alloys", MRS Bulletin 29 (2004) 935-939. (pdf)

  • H. Meco and R.E. Napolitano, “Upper bound velocity limit for free-jet melt spinning”, Mat. Sci. Forum , 475-479 (2004) 3371.

  • R.E. Napolitano, H. Meco, C. Jung, "Faceted solidification morphologies in Al-Si eutectics at low growth rates", J.Metals 56(4) (2004) 16-21. (pdf)

  • M.J.Kramer, H.Meco, K.W. Dennis, E. Varganova, R.W. McCallum, and R.E. Napolitano, C. Jung, H. Meco, "Rapid solidification and metallic glass formation - Experimental and theoretical limits", J. Noncrystalline Solids (2004) (in review).

  • R.E. Napolitano and D.R. Black, "Array ordering in dendritic crystals and the influence on crystal perfection," J. Mat. Sci. 39 (2004) 7009-7017. (pdf)

  • R.E. Napolitano and H. Meco, "The role of melt-pool behavior in free-jet melt spinning," Met. Mat. Trans. 35A (2004) 1539-1553. (pdf)

  • R.E. Napolitano, L.G. England, “High-rate growth-mode transitions in Al-Si eutectics”, in Solidification of Aluminum Alloys, edited by M.G. Chu, TMS, Warrendale, PA (2004) 121-130.

  • J.R. Morris and R.E. Napolitano, "Developments in approaches to determining the anisotropy of the solid-liquid interfacial free energy," J.Metals 56 (4) (2004) 42-46.

  • R.E. Napolitano, S.Liu, and R. Trivedi, "Experimental measurement of anisotropy in crystal-melt interfacial energy," Interface Science 10 (2002) 217-232.

  • S. Liu, R.E. Napolitano, and R. Trivedi, "Measurement of anisotropy of crystal-melt interfacial energy for a binary Al-Cu alloy," Acta Mater. 49 (2001) 4271.

  • R.E. Napolitano, C. Jung, E. Simsek, “In-situ aligned aluminum-silicon composite structures with high interfacial area”, in Proceedings of the Eleventh International Conference on Composites/Nano Engineering, Published by ICCE and the University of New Orleans College of Engineering (2004) 135.

  • R.E. Napolitano, C. Jung, H. Meco, “Growth mechanisms in low-velocity Al-Si eutectics”, in Solidification Processes and Microstructures: A symposium in Honor of W. Kurz, Ed. By M. Rappaz, TMS, Warrendale, PA (2004) 245-250.

  • R.E. Napolitano, "The effect of anisotropy on the equilibrium morphology of a crystal-melt interfacial grain boundary groove," in Int. Conf on Solidification Science and Processing, Outlook for the 21st Century, ed. B.K. Dhindaw, B.S. Murty, and S. Sen, Science Publ. Inc., UK, pp.73-83, 2001.

  • R.E. Napolitano and R.J. Schaefer, "The Convergence-fault mechanism for low-angle boundary formation in single-crystal castings," J.Mater.Sci., 35 (2000) 1641.

  • R. Trivedi, R.E. Napolitano, and Alain Karma, "Dynamical selection of three-dimensional patterns in directional solidification," in Proc. of the NASA Microgravity Materials Science Conference 2000, ed. N. Ramachandran, (2000) 593-598.

  • R.E. Napolitano, A.R. Roosen, and R.J. Schaefer, "The Growth-path method for prediction of stray grain nucleation in single-crystal castings," in Advanced Materials and Processing, eds. M.A. Inman, R. DeNale, S. Hanada, Z. Zhong, and D.N. Lee, TMS, Warrendale, (1998) 1509.

  • R.E. Napolitano and T.H. Sanders, Jr., "Cellular automaton finite difference modeling of alloy solidification using local anisotropy rules," in Computational and Mathematical Models of Microstructural Evolution, eds. J.W. Bullard, L. Chen, R.K. Kalia, A.M. Stoneham, MRS, Warrendale, (1998) 101.

  • R.E. Napolitano and T.H. Sanders, Jr., "Cellular automaton finite difference modeling of morphological evolution during alloy solidification," in Processing of Metals and advanced Materials: Modeling and Design, ed. B.Q. Li, TMS, Warrendale (1998) 63.

  • R.E. Napolitano and T.H. Sanders, Jr., "Competitive growth in quench-modified and impurity-modified aluminum-silicon eutectics," in Proc. of the Fourth International Conference on Aluminum Alloys, eds. T.H. Sanders and E.A. Starke, Georgia Institute of Technology, Atlanta, (1994) 99-107.

  • R.E. Napolitano and T.H. Sanders, Jr., "Modeling morphological evolution during dendritic solidification using a cellular automaton," in advanced materials and processing, eds. M.A.Inman, R. DeNale, S. Hanada, Z. Zhong, and D.N. Lee, TMS, Warrendale, (1998) 1099.

Presentations

    Invited Talks and Seminars

  • R.E. Napolitano, C. Jung, H. Meco, E. Simsek, and Y. Natsume, Faceted primary bicrystalline Si growth in Al-Si alloys, Frontiers in Solidification Science (2nd Biennial), TMS Annual Meeting, Orlando, Florida, February 30, 2007.

  • R.E. Napolitano, Mechanistic selection of faceted silicon growth morphologies, Surface and Interfaces Science at the Atomic Scale, U.S. DOE Workshop, Warrenton, Virginia, October 30, 2006.

  • R.E. Napolitano and H. Meco, Nonequilibrium chemical partitioning and phase formation in rapidly solidified Al-Sm and Ag-Sm binary alloys, THERMEC International Conference on Processing & Manufacturing of Advanced Materials, Vancouver, Canada, July 4, 2006.

  • R.E. Napolitano, Mechanistic selection of silicon growth morphology during solidification of hypereutectic Al-Si alloys, American Association for Crystal Growth, 16th Annual Meeting, Big Sky, Montana, July 10, 2005.

  • R.E. Napolitano and H. Meco, Velocity limits in free-jet melt-spinning, Pacific Rim International Conference on Materials, Beijing, China, November 5, 2004.

  • R.E. Napolitano, C. Jung, E. Simsek, In-situ aligned aluminum-silicon composite structures with high interfacial area, Eleventh International Conference on Composites/Nano Engineering, August 10, 2004.

  • R.E. Napolitano, Measurement of anisotropy in crystal-melt interfacial energy, CECAM meeting: Crystal-Melt Interfaces: Structure, Thermodynamics and Growth, Ecole Normal Superieur, Lyon, France, June 23-25, 2003.

  • R.E. Napolitano, Solid-liquid interfacial properties and their influence on solidification microstructure, Industries of the Future: Iowa Metal Casting Research Initiatives Conference, University of Northern Iowa, November 26, 2002.

    • li class="content">R.E. Napolitano, Branch-limited growth in dendritic crystals, Department of Physics and Astronomy, Condensed Matter Physics Seminar Series, Iowa State University, April 18, 2002.

  • R.E. Napolitano, The role of anisotropic interfacial properties on Solidification Morphology, Seminar, Georgia Institute of Technology, October 7, 2000.

  • R.E. Napolitano and T.H. Sanders, Jr., Cellular Automaton Finite Difference Modeling of Morphological Evolution during Alloy Solidification, Alcoa Technical Center, Pittsburgh, PA, 1997.

  • R.E. Napolitano, An Overview of Cellular Automata and their use in Solidification Modeling, Center for Theoretical and Computational Materials Science, National Institute of Standards and Technology, Gaithersburg, MD, 2/11/97.


    • Other Presentations

  • R.E. Napolitano, C. Jung, and H. Meco, Mechanisms of silicon growth in near-eutectic Al-Si Alloys, Frontiers in Solidification Science, TMS Annual Meeting, San Francisco, CA, Charlotte, February 15, 2005.
  • C. Jung, E. Simsek, and R.E. Napolitano, Three-dimensional aspects of morphological and crystallographic selection in primary Si growth for near-eutectic Al-Si alloys, Symposium on Three-Dimensional Materials Science, TMS Materials Science & Technology (Fall) Meeting, New Orleans, LA, September 27, 2004. (Student delivered talk).
  • R.E. Napolitano, C. Jung, and H. Meco, Growth mechanisms in low-velocity Al-Si eutectics, Solidification Processes and Microstructures: A symposium in Honor of W. Kurz, TMS Annual Meeting, Charlotte, North Carolina, March 17, 2004.
  • R.E. Napolitano and L.G. England, High-rate growth-mode transitions in Al-Si eutectics, Symposium on Solidification of Aluminum Alloys, TMS Annual Meeting, Charlotte, NC, March 15, 2004. (Student delivered talk).
  • R.E. Napolitano, Primary silicon growth mechanisms in Al-Si alloys, DOE Computational Materials Science Workshop, Oak Ridge National Laboratory, March 19, 2004.
  • R.E. Napolitano, Growth mechanisms in Al-Si eutectics, DOE Computational Materials Science Workshop, Colorado School of Mines, October 3, 2003.
  • H. Meco, R.E. Napolitano, and M.J. Kramer, Nucleation and growth during rapid solidification of Fe-Si-B, General Abstracts: Ferrous Materials - Alloy and Stainless Steels, TMS Annual Meeting, Seattle, WA, February, 2002. (Student delivered talk).
  • H. Meco, M.J. Kramer, R.E. Napolitano, M. Sawka, K.W. Dennis, and R.W. McCallum, The use of high speed imaging for thermomechanical characterization of melt-pool dynamics during rapid solidification, Symposium Imaging of Dynamic Processes, TMS Annual Meeting, Seattle, WA, February, 2002. (Student delivered talk).
  • R.E. Napolitano, Solidification of Al-Si eutectics: current understanding and challenges, DOE Computational Materials Science Workshop, University of California, SanDiego, La Jolla, California, March 7, 2003.
  • R.E. Napolitano, Experimental measurement of crystal-melt interfacial properties, DOE Computational Materials Science Workshop, Ames Laboratory, Ames, Iowa, October 21, 2002.
  • R.E. Napolitano, Overview of recent efforts and current challenges in Solidification Science, Department of Energy, Basic Energy Sciences Program Review, Ames Laboratory, Ames, Iowa, May 16, 2002.
  • R.E. Napolitano, Experimental measurement of crystal-melt interfacial properties, DOE Computational Materials Science Workshop, National Institute of Standards and Technology, Gaithersburg, Maryland, March 26, 2002.
  • R.E. Napolitano, J.E. Smugeresky, l.A. Anderson, and D.M. Keicher, In-situ alloying using Freeform Laser Processing, TMS Annual Meeting, Nashville, TN, 3/15/ 00.
  • R.E. Napolitano, Anisotropy of Crystal-Melt Interfacial Energy, TMS Annual Meeting, New Orleans, LA, 2/13/01.
  • R.E. Napolitano, Grain Boundary Groove Morphology and Measurement Strategies for Crystal-Melt Interfacial Properties, DOE Computational Materials Science Workshop, Northwestern University, Evanston, IL, 4/11/00.
  • R.E. Napolitano, Laser Processing for Spatially Distributed Microstructures, Ames Laboratory, Ames, IA, 12/99
  • R.E. Napolitano, Solid-Liquid Interfacial Properties and their Influence on Solidification Morphology, Department of Materials Science and Engineering, Iowa State University, Ames, IA,12/99.
  • R.E. Napolitano, The Convergence Fault Mechanism for Low-Angle Boundary Formation in Single Crystal Castings, Ames Laboratory Metallurgy and Ceramics Program Seminar, Ames, IA, 5/99.
  • R.E. Napolitano, Experimental Advances in Solidification Science, DOE Computational Materials Science Network Workshop, Princeton University, Princeton, NJ, 3/99.
  • R.E. Napolitano and R.J. Schaefer, Grain Defects in Superalloy Single-Crystal Castings, TMS Annual Meeting, 2/99, San Diego, CA.
  • R.E. Napolitano, A.R. Roosen, and R.J. Schaefer, The Growth-Path Method for Prediction of Spurious Grain Nucleation in Single-Crystal Castings, Ames Laboratory, Ames, IA, 7/98.
  • R.E. Napolitano, A.R. Roosen, and R.J. Schaefer, The Growth-Path Method for Prediction of Stray Grain Nucleation in Single-Crystal Castings, TMS Annual Meeting, San Antonio, 1998.
  • R.E. Napolitano, R.J. Schaefer, and B.A. Mueller, Grain Defects in Superalloy Single-Crystal Castings, TMS Annual Meeting, San Antonio, 1998.
  • R.E. Napolitano, R.J. Schaefer, and B.A. Mueller, A Lattice Model of Dendritic Structure in Single- Crystal Castings, TMS Annual Meeting, San Antonio, 1998.
  • R.E. Napolitano, A.R. Roosen, and R.J. Schaefer, The Growth-Path Method for Prediction of Spurious Grain Nucleation in Single-Crystal Castings, TMS Fall Meeting, Rosemont, 1998.
  • R.E. Napolitano and T.H. Sanders, Jr., Quench and Impurity Modified Aluminum-Silicon Eutectics (poster); Georgia Tech Symposium, Atlanta, GA, 2/95.
  • R.E. Napolitano and T.H. Sanders, Jr., Quench and Impurity Modified Al-Si Eutectics, Georgia Tech Symposium, Atlanta, GA, 1995.

Honors and Awards

  • Iowa State University Young Engineering Faculty Research Award, ISU College of Engineering, 2006
  • Department of Materials Science, Excellence in Research Award, Iowa State University, MSE Department, 2004
  • Council of Outstanding Young Engineering Alumni, Georgia Institute of Technology, 2000
  • NRC Postdoctoral Fellowship National Research Council, 1996
  • Outstanding Doctoral Thesis Award Sigma Xi, Scientific Research Society, Georgia Tech Chapter, 1996
  • Student Leadership Scholarship for International Study
  • SAIC Paper Competition Winner Science Applications International Corporation, 1995
  • ASM Leadership Award ASM International, Atlanta Chapter, 1995
  • NSF Traineeship for Composites Research National Science Foundation, 1994
  • TMS Symposium on Superalloys Scholarship The Minerals, Metals, and Materials Society, 1994
  • Inducted into the Alpha Sigma Mu Honorary MSE Fraternity The Georgia Tech Chapter of Alpha Sigma Mu, 1993
  • Grodsky Scholarship, University of Florida, Department of Materials Science and Engineering, 1989

Graduate Students

  • Melis Serefoglu, Current Ph.D. Student
  • Jeong Yun Choi, Current Ph.D. Student
  • Ilkay Kalay, Current MS Student
  • Tim Hosch, Current MS Student
  • Amie Yang, Current MS Student
  • Danny Jorgensen, Current MS Student
  • Choonho Jung, Earned Ph.D. 2006
  • Bryce Rustwick, Earned MS 2005
  • Halim Meco, Earned Ph.D., 2004
  • Luke England, Earned M.S. 2004
  • Melissa Buechler, Earned M.S., 2002

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