Chapter Palestine Polytechnic University Department of Mechanical Engineering ME251: Materials Science Course Objective: Introduce fundamental concepts in Materials Science Syllabus Link: You will learn about: material structure how structure dictates properties how processing can change structure This course will help you to: use materials properly – material selection realize new design opportunities with materials Lecturer: Dr. Maher Al-Jabari

Chapter Concept of Material Science and Engineering Processing Structure Properties level Types

Chapter COURSE OUTLINE AND CALENDER TOPICSWEEKS/HOURS Introduction to Materials Science (Chapter 1)1 st / 2+ Atomic Structure & Interatomic Bonding (Chapter 2)2 nd / 2+ The Structure of Crystalline Solids (Chapter. 3)3 rd -5 th / 8 Short Exam 15 th / 1 Imperfections in Crystals (Chapter 4)6 th -7 th / 4 Diffusion (Chapter 5) -7 th / 2 Mechanical Properties of Metals (Chapter 6)8 th -9 th / 6 Phase Diagrams (Chapter 9)10 th -12 th /9 Midterm Exam13 th /1 Phase Transformation in Metals (Chapter 10)13 th /2 Heat treatment of metals (Chapter 11)14 th /3 Short Exam 215 th /1 Introduction to other materials (Polymers and Ceramics - as time permit) 15 th - rest Final ExamUniversity Schedule

Chapter COURSE POLICIES GRADING SYSTEM Short Exam-110 % Midterm Exam30 % Short Exam-210 % Quizzes and Attendance10 % Final Exam40 % Students are required to attend all classes Unexcused absence of exams is not accepted Make-up exams are expected to be harder.

Chapter Chapter 1 - Introduction What is materials science / engineering ? Why should we know about it? Materials drive our society ??????? History –Stone Age –Bronze Age –Iron Age –Now? Silicon Age? Polymer Age?

Chapter Introduction Structure / Levels: Subatomic (e.g. electron, protons) Atomic (atoms and molecules) Microscopic (grains: large groups) macroscopic (by eye) Property: Response to a specified imposed stimulus Kind and magnitude Processing: Example Heat Treatment Applications: ?

Chapter Example – Biomedical - Hip Implant Requirements –mechanical strength (many cycles) –good lubricity –biocompatibility Femoral Stem Ball Acetabular Cup and Liner

Chapter Other Applications Industry Metal manufacturing Dentists ? Think of Others In Hebron ? In History ? In Future ?

Chapter Developments of New Types of Polymers Commodity plastics Ex.Polyethylene Polypropylene Polystyrene etc. Engineering Resins Ex.Polycarbonate Nylon Polysulfone etc. Can polypropylene be “upgraded” to properties (and price) near those of engineering resins?

Chapter ex: hardness vs structure of steel Properties depend on structure ex: structure vs cooling rate of steel Processing can change structure Structure, Processing, & Properties Hardness (BHN) Cooling Rate (ºC/s) (d) 30  m (c) 4 m4 m (b) 30  m (a) 30  m Just Keep in Mind to the end !

Chapter Types of Materials Metals: Metallic bonding –Strong, ductile –high thermal & electrical conductivity –opaque, reflective. Polymers/plastics: Covalent bonding  sharing of e’s –Soft, ductile, low strength, low density –thermal & electrical insulators –Optically translucent or transparent. Ceramics: Ionic bonding (refractory) – compounds of metallic & non- metallic elements (oxides, carbides, nitrides, sulfides) –Brittle, glassy, elastic –non-conducting (insulators) Others: Composite Materials ? Semi-conductors ?

Chapter Pick ApplicationDetermine required Properties 2. Properties Identify candidate Material(s) 3. Material Identify required Processing Processing: changes structure and overall shape ex: casting, vapor deposition, forming, joining, quenching, annealing. Properties: mechanical, electrical, thermal, magnetic, optical, deteriorative. Material: structure, composition. The Materials Selection Process

Chapter Properties THERMAL ELECTRICAL MAGNETIC OPTICAL

Chapter THERMAL Space Shuttle Tiles: - Silica fiber insulation offers low heat conduction. Thermal Conductivity of Copper: -It decreases when you add zinc! Composition (wt% Zinc) Thermal Conductivity (W/m-K)

Chapter ELECTRICAL Electrical Resistivity of Copper: Adding “impurity” atoms to Cu increases resistivity. Deforming Cu increases resistivity. Adapted from Fig. 18.8, Callister 7e. (Fig adapted from: J.O. Linde, Ann Physik 5, 219 (1932); and C.A. Wert and R.M. Thomson, Physics of Solids, 2nd edition, McGraw-Hill Company, New York, 1970.) T (°C) Cu at%Ni Cu at%Ni deformed Cu at%Ni Resistivity,  (10 -8 Ohm-m) 0 Cu at%Ni “Pure” Cu

Chapter MAGNETIC Magnetic Permeability vs. Composition: --Adding 3 atomic % Si makes Fe a better recording medium! Magnetic Storage: --Recording medium is magnetized by recording head. Magnetic Field Magnetization Fe+ 3% Si Fe

Chapter Transmittance: --Aluminum oxide may be transparent, translucent, or opaque depending on the material structure. single crystal polycrystal: low porosity polycrystal: high porosity OPTICAL

Chapter Strength Fabricability Corrosion Resistance Availability Cost Appearance Factors Material Selection

Chapter Use the right material for the job. Understand the relation between properties, structure, and processing. Recognize new design opportunities offered by materials selection. Do not forget the triangle: Course Goals: SUMMARY Processing Structure Properties