The Structure of Materials

by Allen, Samuel M.; Thomas, Edwin L.

• ISBN13: 9780471000822
• ISBN10: 0471000825
• Edition: 1st
• Format: Paperback
• Copyright: 1999-03-22
• Publisher: Wiley

Summary

Are You Looking for a Unified and Concise Approach to Teaching and Learning the Structure of Materials? Allen and Thomas present information in a manner consistent with the way future scientists and engineers will be required to think about materials' selection, design, and use. Students will learn the fundamentals of three different states of condensed matter-glasses, crystals, and liquid crystals-and develop a set of tools for describing all of them. Above all, they'll gain a better understanding of the principles of structure common to all materials. Key concepts, such as symmetry theory, are introduced and applied to provide a common viewpoint for describing structures of ceramic, metallic, and polymeric materials. Structure-sensitive properties of real materials are introduced. The text also includes a variety of worked example problems. Other texts available in the MIT Series: Thermodynamics of Materials, Vol I, Ragone, 30885-4 Thermodynamics of Materials, Vol II: Kinetics, Ragone, 30886-2 Physical Ceramics: Principles for Ceramics Science and Engineering, Chiang, Birnie, Kingery, 59873-9 Electronic Properties of Engineering Materials, Livingston, 31627-X

Author Biography

About the Authors SAMUEL M. ALLEN is Professor of Physical Metallurgy in the Department of Materials Science and Engineering at M.I.T. He earned a Bachelor of Engineering degree from Stevens Institute of Technology and an S.M. and a Ph.D. from M.I.T. His research interests include phase transformations, solid/solid interfaces, structure/property relations in high-temperature alloys, three-dimensional printing of metal tools for plastic injection molding, and alloys for high-strain actuators. He is also co-authoring a graduate textbook, "Kinetic Processes in Materials," with Robert W. Balluffi and W. Craig Carter. EDWIN L. THOMAS is the Morris Cohen Professor of Materials Science and Engineering at M.I.T. He received a B.S. in Mechanical Engineering from the University of Massachusetts and a Ph.D. in Materials Science from Cornell University. His research interests include processing, microstructure and mechanical property relations of polymers, and optical properties of liquid crystals and polymeric-based photonic band gap materials. Professor Thomas’ honors and awards include the High Polymer Physics Prize of the American Physical Society and the American Chemical Society Creative Polymer Chemist Award.

Table of Contents

Chapter 1 The Structure of Materials: Overview	1	(30)
1.1 Descriptors and Averaging	3	(2)
1.2 Preliminary Concepts	5	(20)
1.2.1 Symmetry	5	(6)
1.2.2 Bonding	11	(1)
Types of Bonds	12	(3)
Structural Descriptors of Bonded Materials	15	(2)
Molecular Geometry	17	(1)
Polyatomic Covalently Bonded Molecules: Electron-Domain Theory	18	(2)
Shape Diversity in Large Molecules and Macromolecules	20	(2)
1.2.3 Coordination Number	22	(1)
1.2.4 Packing Fraction	22	(1)
1.2.5 Order and Disorder	23	(2)
1.3 Structure of Materials Roadmap	25	(3)
References	28	(1)
Additional Reading	28	(1)
Exercises	28	(3)
Chapter 2 Noncrystalline State	31	(58)
2.1 Generic Descriptors	35	(8)
2.1.1 Short-Range Order	35	(2)
2.1.2 The Glass Transition and Free Volume	37	(2)
2.1.3 Pair-Distribution Function	39	(4)
2.1.4 Symmetry of Glass Structure and Physical Properties	43	(1)
2.2 Hard-Sphere Models	43	(8)
2.2.1 Bernal's Random Close-Packed Sphere Model	44	(4)
2.2.2 Voronoi Polyhedra	48	(3)
2.3 Random-Walk Models	51	(12)
2.3.1 Brownian Motion and Diffusion	51	(5)
2.3.2 Polymeric Glasses and Melts	56	(1)
Thermoplastics	57	(3)
Polymer Conformations	60	(1)
Polymer Composition, Architecture and Tacticity	61	(2)
2.4 Network Models	63	(11)
2.4.1 Oxide Glasses	65	(4)
2.4.2 Thermosetting Polymers	69	(3)
2.4.3 Chalcogenide Glasses	72	(1)
Xerography: An Application of Noncrystalline Semiconductors	73	(1)
2.5 Fractal Models	74	(6)
2.5.1 Dilation Symmetry and Fractal Dimension	74	(2)
2.5.2 Ordered Fractals	76	(1)
2.5.3 Irregular Fractals	77	(1)
2.5.4 Diffusion-Limited Aggregation	77	(3)
2.5.5 Fractals and Fracture	80	(1)
References	80	(1)
Additional Reading	81	(1)
Exercises	81	(8)
Chapter 3 Crystalline State	89	(124)
3.1 The Crystallography of Two Dimensions	91	(35)
3.1.1 Translational Symmetry	91	(1)
Lattices	91	(2)
Primitive Cells, Multiple Cells, and Unit Cells	93	(2)
Notation for Rational Points and Rational Lines	95	(2)
3.1.2 Reflectional and Glide Symmetry	97	(2)
3.1.3 Rotational Symmetry	99	(1)
Proper Rotation Axes	99	(2)
Limitation of Rotational Symmetries in Crystals due to Translational Periodicity	101	(2)
3.1.4 Plane Point Groups	103	(1)
Derivation of Plane Point Groups by Combining Reflections and Rotations	103	(3)
General and Special Positions	106	(1)
International and Schoenflies Symbols	107	(1)
3.1.5 The Five Distinct Plane Lattices	108	(1)
Plane Lattice Nets Arising from Crystallographic Rotation Axes and Translations	109	(3)
Lattice Nets Arising from Mirror Lines and Translations	112	(2)
3.1.6 Plane Groups	114	(2)
Addition of Reflectional Symmetry to Plane Lattices	116	(1)
The Seventeen Distinct Crystallographic Plane Groups	117	(2)
3.1.7 The International Tables for Crystallography: Plane Groups	119	(1)
Symbols and Notation	120	(2)
Description of Two-Dimensional Patterns by Crystallographic Data	122	(2)
Generation of Two-Dimensional Patterns from Crystallographic Data	124	(2)
Summary of Information Concerning Plane Groups	126	(1)
3.2 The Crystallography of Three Dimensions	126	(53)
3.2.1 Symmetry Operations Unique to Three Dimensions	126	(1)
Inversion	126	(1)
Rotoinversion	127	(2)
Rotoreflection	129	(1)
Screw Axes	130	(5)
3.2.2 Techniques for Three-Dimensional Spatial Relationships	135	(1)
Rational Intercept Plane: Miller Indices	135	(3)
Direction Common to Two Planes, Zone Axes, Weiss Zone Law	138	(2)
Spherical Trigonometry	140	(3)
Stereographic Projection	143	(3)
3.2.3 Axial Combinations of Rotational Symmetries	146	(1)
Simultaneous Rotational Symmetries	146	(1)
Permissible Combinations of Rotational Axes in Three-Dimensional Crystals	147	(4)
3.2.4 The Thirty-Two Crystallographic Point Groups	151	(1)
Decomposition of Improper Rotation Axes	152	(1)
Derivation of Point Groups by Adding Extenders to Permissible Axial Combinations	153	(5)
Schoenflies Notation for the Crystallographic Point Groups	158	(1)
Laue Groups	159	(1)
3.2.5 Space Lattices	159	(3)
Principles of Derivation by Stacking of Plane Lattices	162	(4)
The Fourteen Bravais Lattices and Six Crystal Systems	166	(2)
Conventional Unit Cells for the Crystal Lattices	168	(2)
3.2.6 Space Groups	170	(1)
Glide Planes	170	(2)
Derivation Method for Space Groups	172	(1)
3.2.7 The International Tables for Crystallography: Space Groups	173	(6)
3.3 Symmetry Constraints on Material Properties	179	(10)
3.3.1 Transformation of a Vector	181	(1)
3.3.2 Transformation of a Tensor	181	(1)
3.3.3 Tensor Properties of Crystals	182	(3)
3.3.4 Symmetry Constraints	185	(4)
3.4 Hard-Sphere Packing and Crystal Structure	189	(7)
3.4.1 Close-Packed Structures	191	(3)
3.4.2 Interstitial Sites in Close-Packed Structures	194	(1)
3.4.3 Close Packing in Ionic Compounds	195	(1)
3.5 Quasicrystals	196	(5)
3.5.1 Aperiodic Tiling Patterns	197	(4)
3.5.2 Icosahedral Structures in Crystals	201	(1)
References	201	(1)
Additional Reading	202	(1)
Exercises	202	(11)
Chapter 4 Liquid-Crystalline State	213	(36)
4.1 Structural Classes of Liquid Crystals	218	(9)
4.1.1 Nematic Phase	220	(1)
4.1.2 Twisted Nematic Phase	221	(2)
4.1.3 Smectic Phase	223	(3)
4.1.4 Columnar Phase	226	(1)
4.2 Descriptors for Liquid Crystals	227	(6)
4.2.1 Pair-Distribution Function	227	(1)
4.2.2 Orientational Order Parameter	228	(3)
4.2.3 Translational Order Parameter	231	(2)
4.3 Mesophase Texture and Identification of Liquid-Crystalline Phases	233	(1)
4.4 Applications of Liquid Crystals	233	(9)
4.4.1 Surfactants	233	(2)
4.4.2 Liquid-Crystalline Fibers	235	(2)
4.4.3 Liquid-Crystal Displays	237	(2)
4.4.4 Next-Generation Flexible Liquid-Crystal Displays	239	(3)
4.5 Plastic Crystals	242	(1)
References	242	(1)
Additional Reading	243	(1)
Exercises	243	(6)
Chapter 5 Imperfections in Ordered Media	249	(100)
5.1 Point Imperfections	251	(20)
5.1.1 Vacancies	251	(4)
5.1.2 Interstitials	255	(2)
5.1.3 Point Imperfections in Molecular Crystals	257	(3)
5.1.4 Mobility of Point Imperfections	260	(1)
5.1.5 Solid Solutions	260	(3)
5.1.6 Point Imperfections in Ionic Crystals	263	(1)
Kroger-Vink Notation	264	(1)
Schottky and Frenkel Imperfections	265	(2)
Imperfections Associated with Impurities	267	(4)
5.2 Line Imperfections	271	(42)
5.2.1 Dislocations	273	(3)
Evidence for Dislocations	276	(4)
Characterization of Dislocations: Tangent Vector and Burgers Vector	280	(3)
Dislocation Motion by Slip and Climb	283	(4)
Dislocation Loops	287	(3)
Slip Systems	290	(4)
Resolved Shear Stress on a Dislocation	294	(4)
Elastic Energy of Dislocations	298	(1)
Strengthening Mechanisms in Crystals	298	(6)
Generation of Dislocations	304	(3)
Dislocations in Columnar Crystals	307	(1)
5.2.2 Disclinations	307	(6)
5.3 Surface Imperfections	313	(27)
5.3.1 Surface Tension and Surface Free Energy	313	(3)
5.3.2 Geometry of Grain Structures	316	(2)
5.3.3 Equilibrium at Interfacial Junctions	318	(3)
5.3.4 Structure of Crystalline Interfaces	321	(1)
Stacking Faults	322	(2)
Antiphase Boundaries	324	(3)
Grain Boundaries	327	(5)
Interphase Grain Boundaries	332	(2)
Grain Boundaries in Block Copolymers	334	(1)
Magnetic Domain Walls	335	(4)
Walls in Liquid Crystals	339	(1)
5.4 Imperfections and Symmetry Breaking	340	(1)
References	340	(1)
Additional Reading	341	(1)
Exercises	341	(8)
Chapter 6 Microstructure	349	(48)
6.1 Structural Hierarchies	350	(7)
6.1.1 Structural Hierarchy in a Metal Forging	352	(2)
6.1.2 Structural Hierarchy in a Semicrystalline Polymer	354	(3)
6.2 Microstructures Arising from Special Processing	357	(22)
6.2.1 Deformation Microstructures	358	(1)
Deformation Processing and Crystallographic Texture	358	(1)
Microstructures of Deformed Polycrystalline Materials	359	(2)
Characterization of Textures: X-Ray Pole Figures	361	(3)
6.2.2 Transformation Microstructures	364	(1)
Solidification Microstructures	364	(6)
Solid-Solid Transformation Microstructures	370	(4)
Composite Microstructures	374	(5)
6.3 Microstructural Case Studies	379	(10)
6.3.1 Nickel-Base Superalloys	380	(5)
6.3.2 Thermoset/Carbon-Fiber Composite Laminates	385	(4)
6.4 Where Do We Go From Here?	389	(2)
References	391	(1)
Additional Reading	391	(2)
Exercises	393	(4)
Index	397