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Stephen Lombardo

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Stephen Lombardo

Stephen Lombardo, Professor

Mechanical and Aerospace Engineering, Chemical Engineering

Stephen Lombardo

Biography

Stephen J. Lombardo is a professor in the Mechanical and Aerospace Engineering Department at the University of Missouri. He is also an adjunct professor in the Department of Biomedical, Biological and Chemical Engineering. Lombardo has several years of industrial experience, having worked for Saint-Gobain Corp. and CeraMem Corp. His research has been financed by the National Science Foundation, the University of Missouri Research Board, the MU Research Reactor and the Petroleum Research Fund, as well as by private businesses such as Alcoa Corp., AlliedSignal, Concurrent Technologies Corp., Honeywell and Procter & Gamble.

Education

  • PhD from the University of California, Berkeley
  • BS from Worcester Polytechnic Institute

Technical Focus

Ceramic materials and ceramic processing
Electronic ceramics
Transport phenomena and kinetics

Peer-Reviewed Publications of Stephen J. Lombardo

68.  “Reaction-Permeability Optimum Time Heating Policy via Process Control for Debinding Green Ceramic Components,” (S. J. Lombardo and D. G. Retzloff) submitted to Advances in Applied Ceramics, 2019.

67.  “Parametric Model for Photovoltaic Cells with Bypass Diodes Under Partial Shading,” (Z. C. Feng and S. J. Lombardo) Journal of Vibration Testing and System Dynamics 3(2) (2019) 107-117.

66.  “A Process Control Algorithm for Reaction-Diffusion Minimum Time Heating cycles for Binder Removal from Green Bodies,” (S. J. Lombardo and D.G. Retzloff) Journal of the American Ceramic Society 102 (2019) 1030-1040.

65.  “Minimum Time Heating Cycles for Diffusion- Versus Permeability-Controlled Binder Removal from Ceramic Green Bodies,” (S. J. Lombardo) Journal of the American Ceramic Society 100 (2017) 529-538.

64.  “Evolved Gas Analysis During Sintering of Barium Titanate,” (M. Moss and S. J. Lombardo) Advances in Applied Ceramics (2016) 264-271.

63.  “Minimum Time Heating Cycles for Diffusion-Controlled Binder Removal from Ceramic Green Bodies,” (S. J. Lombardo) Journal of the American Ceramic Society 98 (2015) 57-65.

62.  “Analytic Model for the Diffusant Concentration in Ceramic Green Bodies During Diffusion-Controlled Thermal Binder Removal,” (S. J. Lombardo) Journal of the American Ceramic Society 96 (2013) 2737-2744.

61.  “Evolved Gas Analysis during the Sintering of Strontium Titanate,” (M. Schurwanz, J. W. Yun, C. S. Kim, and S. J. Lombardo) Advances in Applied Ceramics 111 (2012) 443-449.

60.  “Analytic Method for Determining the Activation Energy of Sintering Using the Master Sintering Curve Approach,” (M. Schurwanz and S. J. Lombardo) Journal of Ceramic Processing Research 13 (2012) 500-507.

59.  “Fabrication Using Filler Controlled Pyrolysis and Characterization of Polysilazane PDC RTD Arrays on Quartz Wafers,” (S. Jung, D. Seo, S. J. Lombardo, Z.C. Feng, J.K. Chen, and Y. Zhang) Sensors and Actuators A: Physical 175 (2012) 53-59.

58. “Plasma Treated Multi-walled Carbon Nanotubes (MWCNTs) for Epoxy Nanocomposites,” (A. Ritts, Q. Yu , H. Li, S. J. Lombardo, X. Han, Z. Xia, J. Lian) Polymers 3 (2011) 2142-2155.

57. “Fabrication and Electrical Properties of Polymer-Derived Ceramic (PDC) Thin Films for High-Temperature Heat Flux Sensors,” (D. Seo, S. Jung, S. J. Lombardo, Z. C. Feng, J. K. Chen, and Y. Zhang) Sensors and Actuators A: Physical 165 (2011) 250-255.

56. “Effects of a Combined Supercritical Extraction/Thermal Cycle on Binder Removal Cycle Time, Yield, and Residual Carbon of Multilayer Ceramic Capacitors,” (B. Abeln and S.J. Lombardo) Journal of Ceramic Processing Research 12 (2011) 515-520.

55.  “Effect of Green Body Size and Heating Rate on Failure during Thermal Debinding and on Debinding Cycle Time,” (R. M. Sachanandani and S. J. Lombardo) Journal of Ceramic Processing Research 12 (2011) 115-121.

54.  “Modeling of Green Body Strength, Internal Pressure, and Stress in Porous Ceramic Bodies During Thermal Debinding” (R. Sachanandani and S. J. Lombardo) Journal of Ceramic Processing Research 12 (2011) 5-11.

53.  “Development of a Heating Schedule for Rapid Thermal Debinding of Green Multilayer Ceramic Capacitors,” (K. Krishnamurthy and S. J. Lombardo) Journal of Ceramic Processing Research 11 (2010) 405-410.

52.  “Teaching Technical Writing in a Lab Course in ChE,” (S. J. Lombardo) Chemical Engineering Education (2010) 58-62.

51.  “Effect of Lamination Conditions for Green Ceramic Tapes on Adhesion Strength, Gas Permeability, and Yield During Binder Removal,” (J. W. Yun, P. J. Scheuer, D. S. Krueger, and S. J. Lombardo) Advances in Applied Ceramics 108 (2009) 488-493.

50.  “Pressure Distribution and Defect Formation in Green Ceramic Bodies During Supercritical Extraction of Binder,” (K. Krishnamurthy and S. J. Lombardo), Journal of the American Ceramic Society 92 (2009) 365-370.

49.  “Determination of Rapid Heating Cycles for Binder Removal from Open-Pore Green Ceramic Components,” (J. W. Yun and S. J. Lombardo) Advances in Applied Ceramics 109 (2009) 92-101.

48.  “Scaling Analysis of the Effect of Binder Content and Binder Distribution on the Gas Permeability of Porous Green Ceramics,” (J. W. Yun and S. J. Lombardo) Journal of the American Ceramic Society 91 (2008) 2150-2155.

47.  “Effect of Lamination Conditions on the Gas Permeability and Adhesion Strength of Green Ceramic Tapes,” (J. W. Yun, P. J. Scheuer, D. S. Krueger, and S. J. Lombardo) Advances in Applied Ceramics 107 (2008) 190-198.

46.  “Curvature and Bifurcation of MgO-Al2O3 Bilayer Ceramic Structures,” (C. S. Kim and S. J. Lombardo) Journal of Ceramic Processing Research 9 (2008) 93-96.

45.  “Permeability of Laminated Green Ceramic Tapes as a Function of Binder Loading,” (J. W. Yun and S. J. Lombardo) Journal of the American Ceramic Society 91 (2008) 1553-1558.

44.  “Methods for Introducing Safety Factors into Minimum Time Heating Cycles for Binder Removal from Green Ceramic Bodies,” (J. W. Yun and S. J. Lombardo), Journal of Ceramic Processing Research 8 (2007) 402-410.

43.  “The Effect of Processing Conditions and Porosity on the Electrical Properties of Y2O3-doped SrTiO3 Internal Boundary Layer Capacitors,” (D. S. Krueger and S. J. Lombardo), Journal of Ceramic Processing Research 8 (2007) 31-37.

42.  “Permeability of Green Ceramic Tapes as a Function of Binder Loading,” (J. W. Yun and S. J. Lombardo) Journal of the American Ceramic Society 90 (2007) 456-461.

41.  “Effect of Processing on the Microstructure and Deformation of MgO-Al2O3, CaO-Al2O3, and SiO2-Al2O3 Layered Composites,” (C. S. Kim and S. J. Lombardo) Journal of Ceramic Processing Research 8 (2007) 43-51.

40.  “Effect of Processing on the Microstructure and Induced Strain Mismatch in Magnesia-Alumina Layered Composites,” (C. S. Kim, R. A. Winholtz, and S.J. Lombardo), Journal of the American Ceramic Society 89 (2006) 2718-2725.

39.  “Heat Transfer Effects in Porous Green Bodies During Binder Removal by Minimum Time Heating Cycles,” (J. W. Yun and S. J. Lombardo), Journal of the American Ceramic Society 89 (2006) 1193-1199.

38.  “Effect of Decomposition Kinetics and Failure Criteria on Binder Removal Cycles From Three-Dimensional Porous Green Bodies,” (J. W. Yun, D. S. Krueger, P. Scheuer, and S. J. Lombardo) Journal of the American Ceramic Society 89 (2006) 176-183.

37. “Adsorption and Diffusion Behavior of Ethane and Ethylene in Sol-Gel Derived Microporous Silica,” (A. C. DeWitt, K. W. Herwig, and S. J. Lombardo) Adsorption 11 (2005) 491-499.

36.  “Ceramics,” S. J. Lombardo, invited entry, Encyclopedia of Chemical Processing, Vol. 1, ed. S. Lee, (Marcel Dekker/Taylor & Francis, NY, 2005) 417-428.

35.  “Strain Induced Deformation in Alumina-Magnesia Layered Composites,” (C. S. Kim, R. A. Winholtz, and S. J. Lombardo) Journal of the American Ceramic Society 88 (2005) 2064-2070.

34.  “A Visual Rankine Cycle Simulation Using Labview,” (P. A. Tebbe, S. J. Lombardo, W. Miller, C. Weisbrook) Computers in Education 14 (2004) 90-96.

33.  “Using Small Blocks of Time for Active Learning and Critical Thinking in the Chemical Engineering Curriculum,” (S. J. Lombardo) Chemical Engineering Education 38 (2004) 150-153.

32.  “Defect Formation during Supercritical Extraction of Binder from Green Ceramic Components, (R. V. Shende, T. R. Redfearn, and S. J. Lombardo) Journal of the American Ceramic Society 87 (2004) 1254-1258.

31.  “Effect of Porosity on the Electrical Properties of Y2O3-doped SrTiO3 Internal Boundary Layer Capacitors,” (D. S. Krueger, R. V. Shende, and S. J. Lombardo), Journal of Applied Physics 95 (2004) 4310-4315.

30.  “Effects of Supercritical Extraction on the Plasticization of Poly(vinyl butyral) and Dioctyl Phthalate Films,” (R. V. Shende, M. Kline, and S. J. Lombardo) Journal of Supercritical 28 Fluids (2004) 113-120.

29.  “Solid State Synthesis, Processing, and Electrical Properties of Sr(TixZr1-x)O3 (0x1) Ceramics for High Voltage Applications,” (R. V. Shende, D. S. Krueger, and S. J. Lombardo) Journal of Ceramic Processing Research 4 (2003) 191-196.

28.  “Determination of the Minimum Time for Binder Removal and Optimum Geometry for Three-Dimensional Porous Green Bodies,” (S. J. Lombardo and Z. C. Feng) Journal of the American Ceramic Society 86 (2003) 2087-2092.

27.  “Analytic Method for the Minimum Time for Binder Removal from Three-Dimensional Porous Green Bodies,” (S. J. Lombardo and Z. C. Feng) Journal of Materials Research 18 (2003) 2717-2723.

26.  “Modeling of the Pressure Distribution in Three-Dimensional Porous Green Bodies during Binder Removal,” (K. Feng and S. J. Lombardo) Journal of the American Ceramic Society 86 (2003) 234-240.

25.  “Kinetic Analysis from Dilatometry and Mass Spectrometry Measurements of the Decomposition and Sintering of Calcium Carbonate,” (K. Feng and S. J. Lombardo) Journal of Ceramic Processing Research 3 (2002) 101-108.

24.  “The Effect of Plaster Composition and Binder Concentration on Strain Mismatch and Deformation of Slip-Cast Green Bodies,” (J. D. Yates and S. J. Lombardo) Materials Science and Engineering: A 337 (2002) 297-305.

23.  “High-Temperature Reaction Networks in Graphite Furnaces,” (K. Feng and S. J. Lombardo) Journal of Materials Science 37 (2002) 2747-2753.

22.  “Pressure Distribution during Binder Burnout in Three-Dimensional Porous Ceramic Bodies with Anisotropic Permeability,” (S. J. Lombardo and Z. C. Feng) Journal of Materials Research 17 (2002) 1434-1440.

21.  “Supercritical Extraction with Carbon Dioxide and Ethylene of Poly(vinyl butyral) and Dioctyl Phthalate from Multilayer Ceramic Capacitors,” (R. V. Shende and S. J. Lombardo) Journal of Supercritical Fluids 23 (2002) 153-162.

20.  “Stress Distribution in Porous Ceramic Bodies During Binder Burnout,” (Z. C. Feng, B. He, and S. J. Lombardo) Journal of Applied Mechanics 69 (2002) 497-501.

19.  “Determination of Binder Decomposition Kinetics for Specifying Heating Parameters in Binder Burnout Cycles,” (R. V. Shende and S. J. Lombardo) Journal of the American Ceramic Society 85 (2002) 780-786.

18.  “Supercritical Extraction of Binder Containing Poly(vinyl butyral) and Dioctyl Phthalate from Barium Titanate-Platinum Multilayer Ceramic Capacitors,” (R. V. Shende, D. S. Krueger, and S. J. Lombardo) Journal of Materials Science: Materials in Electronics 12 (2001) 637-643.

17.  “Strontium Zirconate and Strontium Titanate Ceramics for High-Voltage Applications: Synthesis, Processing, and Dielectric Properties,” (R. V. Shende, D. S. Krueger, G. A. Rossetti, Jr., and S. J. Lombardo) Journal of the American Ceramic Society 84 (2001) 1648-1650.

16.  “Effect of Solids Loading and Dispersant Concentration on Strain Mismatch and Deformation of Slip-Cast Green Bodies,” (J. D. Yates and S. J. Lombardo) Journal of the American Ceramic Society 84 (2001) 2274-2280.

15.  “Optimization of Multi-Layer Ceramic Capacitor Geometry for Maximum Yield during Binder Burnout,” (B. Peters and S. J. Lombardo) Journal of Materials Science: Materials in Electronics 12 (2001) 403-409.

14.  “Role of Length Scale on Pressure Increase and Yield of Poly(vinyl butyral)-Barium Titanate-Platinum Multilayer Ceramic Capacitors During Binder Burnout,” (L. C.-K. Liau, B. Peters, D. S. Krueger, A. Gordon, D. S. Viswanath, and S. J. Lombardo) Journal of the American Ceramic Society 83 (2000) 2645-2653.

13.  “An ‘Open-Ended Estimation’ Design Problem for Thermodynamics Students,” (S. J. Lombardo) Chemical Engineering Education 34 (2000) 154-157.

12.  “Forming of Ceramics during Firing without the Application of External Pressure,” (S. J. Lombardo, D. Bianchi, B. Bishop, A. Giannakopoulos, R. Goldsmith, R. Higgins, R. Pober, S. Suresh) Journal of the American Ceramic Society 82 (1999) 1401.

11.  “The Role of Thermal and Transport Properties on the Binder Burnout of Injection-Molded Ceramic Components,” (A. C. West and S. J. Lombardo) Chemical Engineering Journal 71 (1998) 243-252.

10.  “Simulations of the NO+NH3 and NO+H2 Reactions on Pt(100): Steady State and Oscillatory Kinetics,” (S. J. Lombardo, T. Fink, and R. Imbihl) Journal of Chemical Physics 98 (1993) 5526-5539.

9.  “The NO+NH3 Reaction on Pt(100): Steady State and Oscillatory Kinetics”, (S. J. Lombardo, F. Esch, and R. Imbihl) Surface Science Letters 271 (1992) L367-L372.

8.  “The NO+H2 and NO+NH3 Reactions on Pt(100): Steady State and Oscillatory Kinetics,” (S. J. Lombardo, M. Slinko, T. Fink, T. Löher, H. H. Madden, F. Esch, and R. Imbihl) Surface Science 269/270 (1992) 481-487.

7.  “Raman Spectroscopy and Thermal Desorption of Ammonia on Titania (Anastase)-Supported Vanadia,” (G. T. Went, L.-J. Leu, S. J. Lombardo, and A. T. Bell) Journal of Physical Chemistry 96 (1992) 2235-2241.

6.  “The NO+H2 Reaction on Pt(100): Steady State and Oscillatory Kinetics,” (M. Slinko, T. Fink, T. Löher, H. H. Madden, S. J. Lombardo, R. Imbihl, and G. Ertl) Surface Science 264 (1992) 157-170.

5.  “A Review of Theoretical Models of Adsorption, Diffusion, Desorption, and Reaction of Gases on Metal Surfaces,” (S. J. Lombardo and A. T. Bell) Surface Science Reports 13 (1991) 1-72.

4.  “Monte Carlo Simulations of the Effect of Pressure on Isothermal and Temperature-Programmed Desorption Kinetics,” (S. J. Lombardo and A. T. Bell) Surface Science 245 (1991) 213-224.

3.  “Monte Carlo Simulation of Temperature-Programmed Desorption of Coadsorbed Species,” (S. J. Lombardo and A. T. Bell) Surface Science 224 (1989) 451-475.

2.  “A Monte Carlo Model for the Simulation of Temperature-Programmed Desorption Spectra,” (S. J. Lombardo and A. T. Bell) Surface Science 206 (1988) 101-123.

1.  “Monte Carlo Simulations of Temperature Programmed and Isothermal Desorption from Single Crystal Surfaces,” (S. J. Lombardo) Ph. D. Thesis, University of California, Berkeley, (1990) 1-.

Curriculum Vitae

Stephen J. Lombardo

Departments of Mechanical & Aerospace Engineering and Chemical Engineering
University of Missouri, Columbia, MO 65211
(Phone: 573 884-1644, Fax: 573 884-4940, E-mail: lombardoS@missouri.edu)

SUMMARY OF EDUCATION AND EXPERIENCE

  • 1997-19    University of Missouri, Columbia, MO
  • 1996-97    CeraMem Corporation, Waltham, MA
  • 1992-96    St. Gobain Corporation, Northboro, MA
  • 1991-92    Fritz-Haber Institute of the Max-Planck Society, Berlin, Germany
  • 1985-90       Ph.D. Chemical Engineering, University of California, Berkeley, CA
  • 1983-85    Norton Corporation, Worcester, MA
  • 1979-83    B.S. Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA

UNIVERSITY EXPERIENCE

  • 2003-present    University of Missouri, Columbia, MO
    • Professor in Chemical and Mechanical & Aerospace Engineering:
    • Research areas in the science and processing of ceramic materials for structural, membrane, and electronic applications.  Experimental and modeling programs in powder synthesis, slip casting, thermal binder removal, supercritical extraction of binder, sintering, high temperature chemistry, electrical properties, and transport phenomena in ceramic processing.
  • 1997-2003    University of Missouri, Columbia, MO
    • Assistant Professor in Chemical Engineering

Honors and Awards

  • College of Engineering Faculty Fellowship, (2003-2009)
  • Outstanding Poster Award with Graduate Student Chang Soo Kim, Korean Students Association, University of Missouri, (2005)
  • University of Missouri College of Engineering Teaching Award, (2002)

Patents

  • “Non-Oxidative Tooth Whiteners for Dentifrice Application,” (U.S. Patent No. 11/285,769, filed on 11/22/05)

Professional Society Memberships

  • American Institute of Chemical Engineers
  • American Ceramic Society

Journal Referee for

  • Journal of the American Ceramic Society
  • Journal of Supercritical Fluids
  • Journal of Materials Research
  • Advances in Applied Materials
  • Advances in Applied Ceramics
  • Materials Chemistry and Physics
  • Material Science & Engineering A
  • Journal of the European Ceramic Society
  • Polymer Engineering and Science
  • Chemical Engineering Science
  • Encyclopedia of Chemical Technology
  • Chemical Engineering Education

Proposal Referee for

  • National Science Foundation
  • Petroleum Research Fund
  • University of Missouri Research Board
  • MU Alumni Association
  • MU Research Council

Editorships

  • Editorial Board, Advance in Applied Ceramics, 2009-2012

Courses Taught

  • Ch.E. 3261 Thermodynamics I
  • Ch.E. 3242 Principles of Process Measurement Lab (sometimes Writing Intensive)
  • Ch.E. 4321/7321 Introduction to Ceramics
  • Ch.E. 4370 Process Dynamics and Control
  • Ch.E. 8001 Advanced Ceramic Materials (Graduate)
  • Ch.E. 8001 Properties and Characterization of Ceramic Materials (Graduate)
  • MAE 4231/7231 Transport Phenomena and Materials Processing

EDUCATION

  • 1991-1992    Fritz-Haber Institute of the Max-Planck Society, Berlin, Germany
    • Department of Physical Chemistry. Characterized adsorbates, catalyst surfaces, and surface reactions by mass spectrometry and low energy electron diffraction under ultra high vacuum.  Modeled non-linear phenomena of oscillating surface reactions for improving selectivity between competing reactions.
  • 1985-1990    Ph.D. in Chemical Engineering, University of California, Berkeley, CA
    • Research Advisor: Alexis T. Bell.  Experimental and modeling studies of adsorbate interactions with surfaces including adsorption, desorption, surface diffusion, and surface reaction.
    • Received Graduate Student Outstanding TA Award.
  • 1979-1983    B.S. Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA Graduated with Distinction
    • Tau Beta Pi
    • Phi Lambda Upsilon
    • Chevron Scholarship
    • Junior-year exchange student to Zurich, Switzerland.

INDUSTRIAL EXPERIENCE

  • 1996-1997    CeraMem Corporation, Waltham, MA
    • Research Group Leader. Proposal and execution of government-funded research projects covering the development of novel functionally-graded ceramic materials for use as high-temperature seals. Program Manager on contracts for developing ceramic and polymer membranes and new membrane processes for microfiltration, pervaporation, and gas separation.
  • 1992-1996    St. Gobain Corporation, Northboro, MA
    • Worldwide manufacturer ($20B) of ceramics, abrasives, and materials.
  • Research Associate, Crystar Diffusion Components              1995-1996
    • Provide R&D management ($1.2MM budget) for business supplying recrystallized silicon carbide diffusion components to semiconductor industry.
  • Group Leader, Ceramic Processing Group, Northboro R&D Center     1994-1995
    • Managed R&D group providing corporate-wide processing and materials services to business units. Full P&L and planning responsibility.  Program manager and principal investigator on $1.2M government contract “Ceramic Solid Free Form Technology” using photo-gel polymers. Experience in forming techniques.
  • Senior Research Engineer, Ceramic Processing Group, Northboro R&D 1992-1993
    • Provided processing and characterization of ceramic materials. Principal investigator on government contract for “Reliable Ceramic Processing.”
  • 1983-1985    Norton Company, Worcester, MA.
    • $1.2B worldwide manufacturer of ceramics, abrasives, and materials
  • Research Engineer, High Performance Ceramics, Worcester, MA
    • Powder processing, sintering, and characterization of non-oxide ceramics. Successful transfer of glass encapsulation hot isostatic pressing technology from Swedish company leading to a $7M new ceramic bearing business.

Research Interests

Research Interests in Ceramic Processing and Ceramic Materials

Binder Removal by Thermal Methods

During the processing of ceramics from powders to sintered parts, binder is often added to aid in the handling and processing of the green components. The thermal removal of the binder is often a very slow process requiring days and the yield losses can be high. We have been using a combined modeling and experimental approach to predict rapid binder removal cycles without causing defects in the green body.

Supercritical Extraction of Binder

Supercritical extraction of binder has been used as an alternative processing strategy to rapidly remove binder from green bodies without causing defects in the components. With this methodology, about half of the binder can be removed in as little as three hours.

Synthesis and Processing of Ceramics for Capacitor Applications

To obtain well-defined chemical homogeneity, crystallinity, and porosity, ceramic powders are synthesized by a number of routes, a general attribute of which is that atomic level mixing occurs early in the synthesis process. Powders prepared by these chemical synthesis routes are being evaluated for the application of ceramic capacitors. We have recently synthesized perovskite-type materials having greater than 1000 V/mil (40 V/μm) breakdown strength for use as high-energy density, high voltage capacitors.

Sintering of Ceramics and High Temperature Reactions

The kinetics accompanying the high-temperature sintering of ceramic materials are investigated using combined dilatometry and mass spectrometry. The objective of this work is to develop models for the reaction networks occurring at high temperature and to provide insight into the development of microstructure that occurs at high temperature during sintering.

Lamination, Adhesion Strength and Gas Permeability of Green Ceramic Tapes

In the fabrication of multilayer ceramic capacitors, green sheets are first tape cast and then laminated. To obtain good adhesion between the green tapes, the variables of lamination temperature, pressure, and time can be selected. We have examined in detail the effects of the lamination conditions on the microstructure, adhesion strength, and gas-phase permeability of multilayer green bodies.

Strain Mismatch in Ceramic Processing

We have recently developed a method to shape thin ceramic components at high temperature, without the application of external pressure. To cause this deformation, a coating of a ceramic is applied to a substrate and the strain mismatch which occurs at high temperature leads to curvature in the body. The strain mismatch may arise from cation size effects, phase changes, and differential shrinkage during sintering. The mechanics models which describe the deformation may also have some applicability for describing unwanted deformation in the processing of, for example, LTCC components.

Particle Dynamics

The motion of ceramic particles in a fluid during the forming processes of slip casting, injection molding, and extrusion plays a key role in the development of the microstructure of the body. Both experiments and models are used to probe the role of particle size, size distribution, surface charge, and particle velocity on the evolution of the microstructure during the casting process. We have recently showed how the effects of particle velocity and cake compressibility lead to strain mismatch, and hence bending, in ceramic bodies formed by slip casting. The degree of strain mismatch can be adjusted by modifying the solids loading, the dispersant concentration, or the binder concentration used in the slurry.

Ceramic Membranes

We have recently completed quasi-elastic neutron scattering study of the dynamics of ethylene and ethane in microporous silica membrane material. These adsorbates diffuse in a continuous fashion with rotation playing a role in their mobility in the confined pore space.

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