Table Of Content

Ya. Karpov, V. Demenko, P. Lepikhin, O. Popova, V. Sikulskiy, A. Taran, I. Taranenko, T. Yastremska Series ENGINEERING EDUCATION PHYSICAL PRINCIPLES OF STRUCTURAL MATERIALS SELECTION 2004 Devoted to the 75-th anniversary of the National Aerospace University “Kharkiv Aviation Institute” Recommended by the Ministry of Education and Science of Ukraine as teaching aid for students of higher technical educational institutions Sealed by the Ministry of Education and Science of Ukraine (letter № 14/182-2288.1 dated 21.10.05) MINISTRY OF EDUCATION AND SCIENCE OF UKRAINE INSTITUTE OF CONTENTS AND TEACHING METHODS NATIONAL AEROSPACE UNIVERSITY “KHARKIV AVIATION INSTITUTE” Series ENGINEERING EDUCATION PHYSICAL PRINCIPLES OF STRUCTURAL MATERIALS SELECTION Yakiv Karpov Vladislav Demenko Petro Lepikhin Olena Popova Valeriy Sikulskiy Anatoliy Taran Igor Taranenko Tamara Yastremska Editor-in-Chief Yakiv Karpov Kharkiv 2004 УДК: 620.22 (075.8) UDK: 620.22 (075.8) Фізичні принципи вибору конструкційних матеріалів/ Я.С. Карпов, В.Ф. Деменко, П.П. Лепіхін, О.Г. Попова, В.Т. Сікульський, А.О. Таран, І.М. Тараненко, Т.А. Ястремська. – Навч. посібник. – Харків: Нац. аерокосм. ун-т “Харк. авіац. ін-т”, 2004. – 403 c. Physical Principles of Structural Materials Selection/ Ya. Karpov, V. Demenko, P. Lepikhin, O. Popova, V. Sikulskiy, A. Taran, I. Taranenko, T. Jastremska. – Textbook. – Kharkiv: National Aerospace University “Kharkiv Aviation Institute”, 2004. – 403 p. ISBN 966-662-118-5 Посібник містить основні теоретичні відомості з теорії будови речовини та фізики твердого тіла, необхідні для вивчення спектра функціональних властивостей конструкційних матеріалів і методів керування ними. Розглянуто основні методи механічних випробувань конструкційних матеріалів. Фізико-механічні характеристики матеріалів використані для побудови критеріїв їх раціонального вибору при проектуванні машинобудівних конструкцій, зокрема в авіаційно-космічній галузі. Для студентів, які навчаються за напрямами “Авіація та космонавтика” і “Інженерна механіка”. Може бути використаний для здійснення підготовки з технічного перекладу при вивченні англійської мови у вищих технічних навчальних закладах, а також студентами, які навчаються за спеціальністю “Прикладна лінгвістика”. Іл. 221. Табл. 60. Бібліогр.: 60 назв The Textbook contains principal theoretical information on theory of matter structure and physics of solids, needed for study of wide range of structural materials functional properties as well as the methods how to handle them. The authors considered the main methods of structural materials mechanical testing. Physical and mechanical characteristics of the materials used for development of the criteria of their rational selection in machine designing, in particular, in aerospace field. The Textbook is intended for the students, who are trained in aerospace and mechanical engineering. It may be used for carrying out the technical translation preparation in learning English in higher educational technical institutions as well as for the students, who are trained in “Applied linguistics” specialty. Illustrations 221. Tables. 60. Bibliographical references: 60 names Рецензенти: д-р техн. наук, проф. В.К. Копил, д-р техн. наук, проф. О.Я. Мовшович, д-р техн. наук, проф. C.C. Добротворський Reviewed by: Doctor of Technical Sciences, Professor V. Kopyl, Doctor of Technical Sciences, Professor О. Movshovich, Doctor of Technical Sciences, Professor S. Dobrotvorskiy ISBN 966-662-118-5 © Національний аерокосмічний університет ім. М.Є. Жуковського "Харківський авіаційний інститут", 2004 © Колектив авторів, 2004 © National Aerospace University “Kharkiv Aviation Institute”, 2004 © Group of authors, 2004 CONTENTS Preface..................................................................................................................................................6 Chapter 1 Origin of Materials Internal Structure..........................................................7 1.1 Internal Structure of Materials.........................................................................8 1.1.1 Structure of the Atom......................................................................................9 1.1.2 Electronic Structure of the Atom.....................................................................12 1.1.3 Periodic Table.................................................................................................18 1.1.4 Atomic Bonding..............................................................................................20 1.1.5 Binding Energy and Interatomic Spacing........................................................27 1.2 Atomic Arrangement.......................................................................................29 1.2.1 Short-Range Order Versus Long-Range Order................................................30 1.2.2 Unit Cells........................................................................................................32 1.2.3 Allotropic or Polymorphic Transformations....................................................40 1.2.4 Points, Directions, and Planes in the Unit Cell.................................................41 1.2.5 Interstitial Sites...............................................................................................50 1.2.6 Ionic Crystals..................................................................................................53 1.2.7 Covalent Structures.........................................................................................55 1.3 Imperfections in the Atomic Arrangement.......................................................58 1.3.1 Dislocations....................................................................................................58 1.3.2 Dislocations Movement..................................................................................62 1.3.3 Dislocation Density and Materials Properties..................................................66 1.3.4 Influence of Crystal Structure..........................................................................71 1.3.5 Point Defects...................................................................................................74 1.3.6 Surface Defects...............................................................................................78 1.3.7 Methods of the Slip Process Controlling for Materials Strengthening..............82 1.4 Atom Movement in Materials..........................................................................86 1.4.1 Stability of Atoms and the Arrhenius Equation................................................86 1.4.2 Diffusion Mechanisms....................................................................................87 1.4.3 Activation Energy for Diffusion......................................................................89 1.4.4 Rate of Steady Diffusion (Fick’s First Law)....................................................91 1.4.5 Time of Diffusion...........................................................................................96 1.4.6 Types of Diffusion..........................................................................................97 1.4.7 Fick’s Second Law and Nonsteady Diffusion..................................................98 1.4.8 Kirkendall’s Effect..........................................................................................100 1.4.9 Diffusion in Ionic Compounds and Polymers..................................................101 1.4.10 Importance of a Diffusion in Materials Processing and Properties Changes.....102 1.5 Materials Failure...................................................................................................105 1.5.1 Fracture Mechanism in Metal Failures.................................................................105 1.5.2 Fracture Mechanism in Nonmetal Materials........................................................114 Summary...............................................................................................................115 Chapter 2 The Nature, Types and Properties of Engineering Materials...................117 2.1 Types of Material............................................................................................117 2.2 The Nature of Materials..................................................................................119 2.2.1 The Nature of Metals......................................................................................119 4 CONTENTS 2.2.2 The Nature of Ceramics..................................................................................122 2.2.3 The Nature of Polymers..................................................................................123 2.2.4 The Nature of Composites...............................................................................126 2.2.5 Semiconductors...............................................................................................129 2.3 Properties of Materials. Structure-Property-Processing Relationship................129 2.4 Property Spectrum..........................................................................................133 2.4.1 Chemical Properties........................................................................................133 2.4.2 Physical Properties..........................................................................................136 2.4.3 Mechanical Properties.....................................................................................144 2.5 Processing and Properties................................................................................148 2.6 Environmental Effects on Material Behavior...................................................150 Summary...............................................................................................................153 Chapter 3 Mechanical Testing and Properties Determination...................................155 3.1 Tensile Tests...................................................................................................156 3.1.1 Stress–Strain Diagram.....................................................................................157 3.1.2 Engineering Stress and Strain..........................................................................158 3.1.3 Properties Obtained from the Tensile Test.......................................................161 3.1.3.1 Yield Strength.................................................................................................162 3.1.3.2 Tensile Strength..............................................................................................163 3.1.3.3 Modulus of Elasticity......................................................................................164 3.1.3.4 Poisson's Ratio................................................................................................166 3.1.4 True Stress–True Strain...................................................................................167 3.1.5 Shear Strength.................................................................................................169 3.1.6 Temperature Effects in Materials.....................................................................169 3.1.7 Brittle Behavior...............................................................................................170 3.2 Impact Test.....................................................................................................172 3.2.1 Types of Impact Test.......................................................................................172 3.2.2 Transition Temperature...................................................................................174 3.2.3 Notch Sensitivity...................................................................................................175 3.2.4 Relationship to Stress-Strain Diagram.............................................................175 3.2.5 Use of Impact Properties.................................................................................177 3.3 Fatigue Test....................................................................................................177 3.3.1 Nature of the Fatigue Test...............................................................................177 3.3.2 Results of the Fatigue Test..............................................................................180 3.3.2.1 Fatigue Life...........................................................................................................180 3.3.2.2 Endurance Limit.............................................................................................180 3.3.2.3 Fatigue Strength..............................................................................................181 3.3.2.4 Notch Sensitivity in Fatigue............................................................................181 3.3.2.5 Endurance Ratio..............................................................................................181 3.3.2.6 Temperature Effect in Fatigue.........................................................................182 3.4 Creep Test.......................................................................................................183 3.4.1 Nature of Creep Test.......................................................................................183 3.4.2 Dislocation Climb in Creep.............................................................................183 3.4.3 Creep Rate and Rupture Time.........................................................................185 3.4.4 Use of Creep Data...........................................................................................186 CONTENTS 5 3.5 Hardness Test..................................................................................................189 3.5.1 Nature of Hardness Test..................................................................................189 3.5.2 Use of Hardness Test for Material Selection....................................................190 3.6 Fracture Characteristics...................................................................................191 3.6.1 Introduction to Fracture Mechanics.................................................................191 3.6.2 Importance of Fracture Characteristics in Design.............................................195 3.7 Dimensional Properties...................................................................................196 3.7.1 Main Definitions.............................................................................................196 3.7.2 Surface Finish.................................................................................................196 3.7.3 Size and Shape Considerations in Material Selection.......................................198 Summary...............................................................................................................202 Chapter 4 General Principles of Material Selection....................................................203 4.1 The Design Process and Material Selection.....................................................203 4.2 Selection Factors.............................................................................................205 4.2.1 Availability.....................................................................................................207 4.2.2 Economics......................................................................................................207 4.2.3 Properties........................................................................................................212 4.2.4 Summary........................................................................................................213 4.3 Material Property Charts.................................................................................213 4.4 The Material–Property Diagrams Review........................................................221 4.4.1 The Modulus–Density Chart (Chart 1)............................................................221 4.4.2 The Strength–Density Chart (Chart 2).............................................................225 4.4.3 The Fracture Toughness–Density Chart (Chart 3)............................................227 4.4.4 The Modulus–Strength Chart (Chart 4)...........................................................228 4.4.5 The Fracture Toughness-Modulus Chart (Chart 5)...........................................231 4.4.6 The Fracture Toughness–Strength Chart (Chart 6)...........................................233 4.4.7 The Loss Coefficient–Modulus Chart (Chart 7)...............................................236 4.4.8 The Thermal Conductivity–Thermal Diffusivity Chart (Chart 8).....................238 4.4.9 The Thermal Expansion–Modulus Chart (Chart 9)..........................................240 4.4.10 The Normalized Strength–Thermal Expansion Chart (Chart 10)......................243 4.5 Conclusions and Applications.........................................................................245 4.6 An Example of Material Selection for a Typical Machine Part........................246 4.7 Materials for Typical Machine Components....................................................251 Summary...............................................................................................................255 Appendixies..........................................................................................................................................257 Appendix A Symbols, Dimensions, and Units................................................258 Appendix B Fundamental Constants...............................................................291 Appendix C Table of Elements........................................................................295 Appendix D Selected Physical Properties of Metals.....................................301 Appendix E Properties of Selected Engineering Materials..........................303 Appendix F Unified Numbering System.........................................................341 Appendix G Important Terms..........................................................................348 References...........................................................................................................................................400 PREFACE The original goal of this text is to present materials information that a designer needs to know in order to select materials for the structure in engineering design based on physical principles of materials science. The designer must know not only something about all types of structural materials (plastics, metals and so on), their properties, their limitations, but how to specify them properly in engineering drawing or in design specifications. Designer’s understanding of the relationship between structure and properties provides the basis for both his/her selection of existing materials and his (her) development of new materials. A modern designer must be able to engineer the electronic and atomic structure of materials in order to produce miniaturized electronic and optical devices. By manipulating molecular structure, we have produced a vast spectrum of polymers capable of operating under extreme conditions including elevated temperatures of wear. Controlling microstructure has led to many new metal alloys and ceramics, including light weight aerospace alloys and ceramic superconductors. And we have played wizard, juggling the structure of composites to produce unique properties. The methods used to control the microstructure and macrostructure of materials are examined to find out the fact that by controlling the structure we in turn can control the mechanical properties. Before looking at the processes used to control the strengthening mechanisms, the mechanical testing of materials needs to be considered. The results of mechanical tests are the mechanical properties of materials. They are used to produce effective material selection, which requires that a designer should be familiar with common materials systems and should be able to choose a repertoire of specific materials from the system as well as must know how to use a material effectively. The modern method of material selection is discussed, using physically based relationships between chemical, physical and mechanical properties. The text can serve, first, those students the course of engineering materials had been formally introduced to and who will not be involved in this field in future. Such students need a basic understanding of materials, the types of materials behavior so that they could appropriately select materials and, second, this text can introduce the science of materials, the types of materials available, and the application of materials by materials-oriented students in engineering. These students will go on studying the details of materials structure and properties in more advanced courses. We believe that to read this text, a student must be sure to have sufficient exposure to chemistry, physics, and mathematics. The experience gained will be useful to provide students with fundamental knowledge in materials manufacturing, processing or selection. Chapter 1 Origin of Materials Internal Structure All engineers are involved with materials on a daily basis. We manufacture and process materials, design and construct components or structures using materials, select materials, analyze failures of materials, or simply hope the materials we are using perform adequately. We are interested in improving the performance of the product we are designing or manufacturing. Electrical engineers want integrated circuits to perform properly, switches in computers to reach instantly , and insulators to withstand high volt- ages even under the most adverse conditions. Civil engineers wish to construct reli- able structures that are resistant to corrosion. Petroleum and chemical engineers re- quire drill bits or piping that survive in abrasive or corrosive conditions. Automotive engineers desire light weight yet strong and durable materials. Aerospace engineers demand light weight materials that perform well both at high temperatures and in the cold vacuum of outer space. Metallurgical, ceramic, and polymer engineers wish to produce and shape materials that are more economical and possess improved properties. Each of developed products requires materials with specified characteristic such that (1) the material can be processed into the final products satisfactorily and economically and (2) the products will behave appropriately in service. Since the engineer must specify the materials for TV sets, computers, suspen- sion bridges, oil refineries, rocket motors, nuclear reactors, or supersonic transports he must have sufficient knowledge to select the optimum material for each applicant taking into account material availability, processing requirements, service demands, and the ever-important cost factor, in addition to the design specification which match the part to the system as a whole. Although experience provides the engineer with a starting point for selection of materials, and the property data found in hand- books will aid him, the skill of the engineer will be limited unless he understands the factors, which contribute to the properties of materials. Without this knowledge, a material is simply a "black box" and the engineer will have no conception of the material's limitations, or of possible modifications in materials selection and design. The intent of this Chapter is to permit the student to become aware of the types of materials available, to understand their general behavior and capabilities, and to recognize the effects of the environment and service conditions on the materials performance.