UNIVERSITY OF TWENTE. M Advanced Ceramics Processing Lecture notes UT-c0de:193737010 Louis Winnubst University of Twente Inorganic Membranes Faculty of Science and Technology P.0.B0x217 7500 AE Enschede The Netherlands e-mail:a.j.a.winnubst@utwente.nl October 2019
UNIVERSITY OF TWENTE. Advanced Ceramics Processing Lecture notes UT-code: 193737010 Louis Winnubst University of Twente Inorganic Membranes Faculty of Science and Technology P.O. Box 217 7500 AE Enschede The Netherlands e-mail: a.j.a.winnubst@utwente.nl October 2019
Preface These lecture notes are intended for a course on Advanced Ceramics Processing of in. oncesemphasized for understanding the effects of pro essing variables on the evolution of the ceramic microstructure during the fabrication process.If one has sufficient insight in the several process steps it is possible to make a reproducible material with regard to properties and micro- structure The objective in materials process engineering is to find relations between(desired)materials properties and relevant microstructural parameters on one side and to understand which process parameter change eter on the other han igiomeaienorptoiogesmdpcecheompihdl0ypostionmsalieszeamdagregaeor The integral ceramic fabrication process is divided into the following process steps or basic pro- cess powder reparat nts like milling and mixing Forming into a green shape ·Coating techniques 。Sintering in n the microstruc ure.The oontoland steps in a coherent way. The following basic phenmn will be treated in thecourse for obtaininga better understanding of teristies Particle siz Interaction between particles (ag and particlem ion stability,rheology,etc.) Reactions between solid state particles Nucleation and crystallisation
3 Preface These lecture notes are intended for a course on Advanced Ceramics Processing. The aim of this course is to obtain insights in processes, which play a role in the fabrication of inorganic (or ceramic) materials and ceramic coatings. The fabrication process is treated and the importance is emphasized for understanding the effects of processing variables on the evolution of the ceramic microstructure during the fabrication process. If one has sufficient insight in the several process steps it is possible to make a reproducible material with regard to properties and microstructure. The objective in materials process engineering is to find relations between (desired) materials properties and relevant microstructural parameters on one side and to understand which process parameter changes a certain microstructural parameter on the other hand. The microstructure includes characteristics like crystal structure, chemical composition, crystallite size and aggregate or agglomerate morphology, pore size and pore morphology. The integral ceramic fabrication process is divided into the following process steps or basic processes: • Powder preparation • Powder treatments like milling and mixing • Forming into a green shape • Coating techniques • Sintering Each step has its specific influence on the microstructure. Therefore control and knowledge of the whole process is important. Optimal properties require optimisation and control of each of these steps in a coherent way. The following basic phenomena will be treated in the course for obtaining a better understanding of the basic processes: • Particle characteristics: Particle size and particle morphology • Interaction between particles (agglomeration, suspension stability, rheology, etc.) • Reactions between solid state particles • Nucleation and crystallisation
Literature er the broad field of ce Carter and Grant Norton "Ceramic Materials:Science and Engineering"Springer, J.S.Reed,"Principles of Ceramic Processing"2nd edition,John Willey Sons (New York) 1995(SBN0-471-59721-X. TARi mic powder processing and synthesis"Academic Press(San Dieg0)1996(1SBN0-12-588930-5 ·D02 Richerson,"Modern Ceramic Engineering"2nd Edition,Marcel Dekker (New York) A.R.West"Solid State Chemistry and its Applications"John Willey Sons(Chichester)1984 55 Sons (Chichester)199(ISBN0-471-95627-) a,"The chemistry of ceramics"John Willey .R.A.Terpstra,P.P.A.C.Pex and A.H.de Vries"Ceramic Processing"Chapman Hall (Lon- om)1995(0s BN0-4 2-59830-2) Plcnum der D.SegaChemical synthesis of advanced ceramic materials"Cambridge University press (Cambridge)199
4 Literature. The following books cover the broad field of ceramic process engineering: M.N. Rahaman, “Ceramic Processing” CRC Taylor & Francis (Boca Raton, London, New York) 2007 (ISBN 0-8493-7285-2). C.B. Carter and M. Grant Norton “Ceramic Materials: Science and Engineering” Springer, 2007 J.S. Reed, “Principles of Ceramic Processing” 2nd edition, John Willey & Sons (New York) 1995 (ISBN 0-471-59721-X). W.D. Kingery, H.K. Bowen, D.R. Uhlmann, “Introduction to Ceramics” 2nd edition, John Wiley & Sons (New York) 1976. T.A Ring, “Fundamentals of ceramic powder processing and synthesis” Academic Press (San Diego) 1996 (ISBN 0-12-588930-5). D.W. Richerson, “Modern Ceramic Engineering” 2nd Edition, Marcel Dekker (New York) 1992. Y.M. Chiang, D. Bernie III, W.D. Kingery, “Physical ceramics; Principles for ceramic science and engineering”, John Wiley & Sons, Inc. (New York) 1997 (ISBN 0-471-59873-9). A.R. West “Solid State Chemistry and its Applications” John Willey & Sons (Chichester) 1984 (ISBN 0-471-90337-9). H. Yanagida, K. Koumoto and M. Miyayama, “The chemistry of ceramics” John Willey & Sons (Chichester) 1996 (ISBN 0-471-95627-9). R.A. Terpstra, P.P.A.C. Pex and A.H. de Vries “Ceramic Processing” Chapman & Hall (London) 1995 (ISBN 0-412-59830-2). P.J. van der Put “The inorganic chemistry of materials: How to make things out of elements” Plenum press (New York, London) 1998. D. Segal, “Chemical synthesis of advanced ceramic materials” Cambridge University press (Cambridge) 1989. D.H. Everett “Basic principles of colloid science” Royal Society of Chemistry (Cambridge) 1988 (ISBN 0-85186-443-0)
5 Contents Preface Contents 5 Introduc 11 The process-microstructure and homogeneity 77 Fabrication of bulk ceramics Phase diagrams in ceramics 2.2 Particle morphology 18 2.41 light scatter haracterisation method 91 242 Flow behaviour of powders 23 2.5 3 Interactions betwe owder 3.1 ates 3.2 Particles in a solvent;the DLVO theory 322 3.2. The DLVO potential 34 3.3 Rheology onian fluic heha 15156 Shear rate- 6 334 Time-dependent behaviour 3.3. 3.4 Weissenberg effects Solid state mechanics 94号 Reaction betwe n solid narticle 41 An introduction to solid state diffusion state reactions reaction and coating 5.1.1 Theory 3 5.1.2 ample Dispersion methods of mixed metal oxide powders 5.2.1 3366 52.2 Co-Precipitation Complexation- Sol-Ge plexation-Pyrolysis 8990
5 Contents Preface 3 Contents 5 1 Introduction 7 1.1 The process – microstructure and homogeneity 7 1.2 Fabrication of bulk ceramics 9 1.3 Phase diagrams in ceramics 11 2 Characteristics of powders and compacts 15 2.1 Definitions of ceramic powders 15 2.2 Particle morphology 18 2.3 Particle size distribution 19 2.4 Chemical and physical characterisation methods 21 2.4.1 Dynamic light scattering 21 2.4.2 Flow behaviour of powders 23 2.5 Compact characteristics 23 2.5.1 Characterization of porosity, pore size and pore size distribution 24 3 Interactions between powder particles 27 3.1 Adhesive forces in agglomerates 27 3.2 Particles in a solvent; the DLVO theory 29 3.2.1 Electrostatic forces around a single particle; the electric double layer 29 3.2.2 Van der Waals attraction 33 3.2.3 The DLVO potential 34 3.3 Rheology 35 3.3.1 Newtonian fluid 35 3.3.2 Non-Newtonian behaviour 36 3.3.3 Shear rate-dependent behaviour 36 3.3.4 Time-dependent behaviour 39 3.3.5 Weissenberg effects 41 3.4 Solid state mechanics 43 4 Reaction between solid particles 45 4.1 An introduction to solid state diffusion 45 4.2 Mechanisms of solid state reactions 47 4.3 Kinetics of solid-solid reactions 49 5 Preparation of ceramic powders and coatings 53 5.1 Nucleation, crystallisation and crystal growth 53 5.1.1 Theory 53 5.1.2 Examples 53 5.2 Wet chemical preparation of mixed metal oxide powders 56 5.2.1 Dispersion methods 56 5.2.2 Co-Precipitation 58 5.2.3 Complexation-Precipitation 59 5.2.4 Complexation-Pyrolysis 59 5.3 Sol-Gel 60
34 Preparation from the gas phase reparatio from the (partly)melted phasc 6 Treatments of powders 6.1 Milling or comminution 83 Mixing 6.3.1 6.3.2 Press granulation 5555556 6.3.3 Spray drying 7 7.1.1 Powder properties 555 Filling the die or mould cro: Dry pre ssing in nr 9924 7.1.6 Special techniques in dry pressing 7.2 sion processing 723 Centrifugal castins 1eT33 7.3 726 Paste processing 73.1 Extrusion 7.3.2 Injection moulding 8 cessing of green compacts ing 82 Binder burn-out 9 force in solid state sinter 80 9.2.1 9.2.2 Grain growth and densification 9 ering Curve (MSC) 9.5 Reactive sintering 9.6 Special sintering techniques 96 963 9.6.4 Spark Plasma Sintering 9.7 Practical aspects of sintering 07 9000000 972 Temperature control 9.7.3 Atmosphere and additives 01
6 5.4 Preparation from the gas phase 61 5.5 Preparation from the (partly) melted phase 62 6 Treatments of powders 65 6.1 Milling or comminution 65 6.2 Mixing 65 6.3 Granulation (controlled agglomeration) 65 6.3.1 Layering granulation 65 6.3.2 Press granulation 65 6.3.3 Spray drying 66 7 Processes for compaction 67 7.1 Dry pressing 67 7.1.1 Powder properties 69 7.1.2 Filling the die or mould 69 7.1.3 Microstructure development during dry pressing 69 7.1.4 Die-wall friction during uniaxial compaction 72 7.1.5 Dry pressing in practice 74 7.1.6 Special techniques in dry pressing 75 7.2 Suspension processing 75 7.2.1 Slip casting 75 7.2.2 Colloidal filtration 76 7.2.3 Centrifugal casting 76 7.2.4 Tape casting 77 7.2.5 Other suspension/slurry techniques 81 7.2.6 Coatings from suspensions 82 7.3 Paste processing 82 7.3.1 Extrusion 82 7.3.2 Injection moulding 83 8 Thermal processing of green compacts 85 8.1 Drying 85 8.2 Binder burn-out 85 9 Sintering 89 9.1 Driving force in solid state sintering 90 9.2 The (solid state) sintering process 91 9.2.1 The coordination model 93 9.2.2 Grain growth and densification 96 9.3 Liquid phase sintering 97 9.4 The Master Sintering Curve (MSC) 97 9.5 Reactive sintering 98 9.6 Special sintering techniques 98 9.6.1 Pressure sintering 98 9.6.2 Microwave and RF sintering 99 9.6.3 Fast firing 99 9.6.4 Spark Plasma Sintering 100 9.7 Practical aspects of sintering 100 9.7.1 Furnaces 100 9.7.2 Temperature control 101 9.7.3 Atmosphere and additives 101