1 / 19

Palestine Polytechnic University Department of Mechanical Engineering ME251: Materials Science

Palestine Polytechnic University Department of Mechanical Engineering ME251: Materials Science. Lecturer: Dr. Maher Al-Jabari. Course Objective: Introduce fundamental concepts in Materials Science

Download Presentation

Palestine Polytechnic University Department of Mechanical Engineering ME251: Materials Science

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Palestine Polytechnic UniversityDepartment of Mechanical EngineeringME251: Materials Science Lecturer: Dr. Maher Al-Jabari Course Objective: Introduce fundamental concepts in Materials Science Syllabus Link:http://cet.ppu.edu/depts/me/metemplate/syllabus/maher_s/Material%20Sc%20SYLLABUS.htm 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

  2. Concept of Material Science and Engineering Processing Structure Properties Types level

  3. COURSE OUTLINE AND CALENDER

  4. COURSE POLICIES GRADING SYSTEM Short Exam-1 10 % Midterm Exam 30 % Short Exam-2 10 % Quizzes and Attendance 10 % Final Exam 40 % Students are required to attend all classes Unexcused absence of exams is not accepted Make-up exams are expected to be harder.

  5. 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?

  6. 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: ?

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

  8. Other Applications • Industry • Metal manufacturing • Dentists ? • Think of Others • In Hebron ? • In History ? • In Future ?

  9. 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?

  10. Structure, Processing, & Properties (d) 30mm (c) (b) (a) 4mm 30mm 30mm • Properties depend on structure ex: hardness vs structure of steel 6 00 5 00 4 00 Hardness (BHN) 3 00 Just Keep in Mind to the end ! 2 00 100 0.01 0.1 1 10 100 1000 Cooling Rate (ºC/s) • Processing can change structure ex: structure vs cooling rate of steel

  11. 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 ?

  12. The Materials Selection Process 1. Pick Application Determine required Properties Properties: mechanical, electrical, thermal, magnetic, optical, deteriorative. 2. Properties Identify candidate Material(s) Material: structure, composition. 3. Material Identify required Processing Processing: changes structure and overall shape ex: casting, vapor deposition, forming, joining, quenching, annealing.

  13. Properties • THERMAL • ELECTRICAL • MAGNETIC • OPTICAL

  14. 400 300 (W/m-K) 200 Thermal Conductivity 100 0 0 10 20 30 40 Composition (wt% Zinc) THERMAL • Space Shuttle Tiles: - Silica fiber insulation offers lowheat conduction. • Thermal Conductivity of Copper: -It decreases when you add zinc!

  15. 6 5 Cu + 3.32 at%Ni 4 Cu + 2.16 at%Ni Resistivity, r deformed Cu + 1.12 at%Ni 3 (10-8 Ohm-m) 2 Cu + 1.12 at%Ni 1 “Pure” Cu 0 -200 -100 0 T (°C) ELECTRICAL • Electrical Resistivity of Copper: Adapted from Fig. 18.8, Callister 7e. (Fig. 18.8 adapted from: J.O. Linde, Ann Physik5, 219 (1932); and C.A. Wert and R.M. Thomson, Physics of Solids, 2nd edition, McGraw-Hill Company, New York, 1970.) • Adding “impurity” atoms to Cu increases resistivity. • Deforming Cu increases resistivity.

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

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

  18. Material Selection Factors • • Strength • Fabricability • Corrosion Resistance • Availability • Cost • Appearance

  19. SUMMARY Course Goals: • 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: Processing Structure Properties

More Related