Material Technology.pdf - Alexandria University Faculty of...

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Alexandria University Faculty of Engineering Department of Naval Architecture and Marine Engineering Course Title : Material Technology Code : MR 242 Year : 2 nd Marine Semester : Second Weekly Hours : 4 [ Lecture (3) , Tutorial (1) ] Marks : 100 [ Class (30) , Final (70) ] Exam Duration : 3 Hours Lecturer : Dr . Ahmed Saeed Zayed
Alexandria University Faculty of Engineering Department of Naval Architecture and Marine Engineering Material Technology (MR 242) 2 nd Marine 2 Course Contents 1. Introduction ........................................................................................................................ 6 1.1. Materials Science and Engineering ............................................................................. 6 1.2. Classification of Materials .......................................................................................... 7 1.2.1. Metals ................................................................................................................... 7 1.2.2. Ceramics .............................................................................................................. 7 1.2.3. Polymers .............................................................................................................. 8 1.2.4. Composites ........................................................................................................... 9 1.3. Advanced Materials ..................................................................................................... 9 1.3.1. Semiconductors .................................................................................................... 9 1.3.2. Biomaterials ....................................................................................................... 10 1.3.3. Materials of the Future ....................................................................................... 10 1.3.3.1. Smart Materials ........................................................................................... 10 1.3.3.2. Nanoengineered Materials .......................................................................... 10 2. The Structure of Crystalline Solids .................................................................................. 11 2.1. Metallic Crystal Structures ........................................................................................ 11 2.1.1. The Face-Centered Cubic Crystal Structure ...................................................... 11 2.1.2. The Body-Centered Cubic Crystal Structure ..................................................... 13 2.1.3. The Hexagonal Close-Packed Crystal Structure ................................................ 13 2.2. Density Computations ............................................................................................... 14 2.3. Polymorphism and Allotropy .................................................................................... 15 2.4. Single Crystals ........................................................................................................... 15 2.5. Polycrystalline Materials ........................................................................................... 16 2.6. Anisotropy ................................................................................................................. 16 2.7. Noncrystalline Solids ................................................................................................ 17 3. Imperfections in Solids .................................................................................................... 19 3.1. Point Defects ............................................................................................................. 19 3.1.1. Vacancies and Self-Interstitials .......................................................................... 19 3.1.2. Impurities in Solids ............................................................................................ 20 3.2. Dislocations—Linear Defects ................................................................................... 21 3.3. Interfacial Defects ..................................................................................................... 23 3.3.1. External Surfaces ............................................................................................... 24 3.3.2. Grain Boundaries ............................................................................................... 24
Alexandria University Faculty of Engineering Department of Naval Architecture and Marine Engineering Material Technology (MR 242) 2 nd Marine 3 3.3.3. Twin Boundaries ................................................................................................ 26 3.4. Bulk or Volume Defects ............................................................................................ 26 4. Strengthening in Metals ................................................................................................... 27 4.1. Strengthening by grain size reduction ....................................................................... 27 4.2. Solid-solution strengthening ..................................................................................... 29 4.3. Strain hardening ........................................................................................................ 30 5. failure ............................................................................................................................... 33 5.1. Fracture ...................................................................................................................... 33 5.1.1. Ductile fracture .................................................................................................. 34 5.1.2. Brittle fracture .................................................................................................... 36 5.2. Fatigue ....................................................................................................................... 37 5.2.1. Cyclic stresses .................................................................................................... 37 5.2.2. The S–N Curve .................................................................................................. 39 5.2.3. Crack initiation and propagation ........................................................................ 40 5.2.4. Factors that affect fatigue life ............................................................................ 40 5.2.4.1. Mean Stress ................................................................................................. 40 5.2.4.2. Surface Effects ............................................................................................ 41 5.2.4.3. Environmental effects ................................................................................. 43 5.3. Creep ......................................................................................................................... 44 5.3.1. Factors affect creep ............................................................................................ 45 6. Phase Diagrams ................................................................................................................ 47 6.1. Phases ........................................................................................................................ 47 6.2. One-component (or unary) phase diagrams .............................................................. 47 6.3. Binary phase diagrams .............................................................................................. 49 6.3.1. Binary isomorphous systems ............................................................................. 49 6.3.2. Interpretation of phase diagrams ........................................................................ 51 6.3.2.1. Phases Present ............................................................................................. 51 6.3.2.2. Determination of Phase Compositions ....................................................... 51 6.3.2.3. Determination of Phase Amounts ............................................................... 52 6.3.3. Development of microstructure in isomorphous alloys ..................................... 55 6.3.3.1. Equilibrium Cooling ................................................................................... 55 6.3.3.2. Nonequilibrium Cooling ............................................................................. 55 6.3.4. Binary eutectic systems ...................................................................................... 57 6.3.5. Equilibrium diagrams having intermediate phases or compounds .................... 63 6.3.6. Eutectoid and Peritectic reactions ...................................................................... 63