Materials Science & Engineering Course Objective... Introduce fundamental concepts in MSE You will learn about: • material structure Objective of this course is to introduce you to the fundamental concepts in Materials Science and Engineering… Achieve this goal by explaining the structure of materials, then by investigating the structure-property relationship we will venture into how structure impacts materials properties, and finally we will go over the processes used to optimize the structure of materials used to attain desired properties… At the end of this course, the expectation is that you will learn how to choose and use right materials for the right application. Furthermore, by expanding your knowledge about materials properties, you can realize new design opportunities with materials… • how structure dictates properties • how processing can change structure This course will help you to: • use materials properly • realize new design opportunities with materials a

LECTURES Lecturer: Goknur Cambaz Buke Time: PLEASE BE ON TIME Location: A 319 Activities: • Present new material • Announce reading and homework • Take quizzes and midterms* *Make-ups given only for emergencies. *Discuss potential conflicts beforehand. b

About me ! Education: B.Sc.: METU, Materials and Metallurgical Engineering M.Sc.:METU, Materials and Metallurgical Engineering Ph.D.: Drexel University, Nanotechnology institute, Materials Science and Engineering, USA

Contact me for other special arrangements! OFFICE HOURS 10:00-12:00 Friday Contact me for other special arrangements! Activities: • Discuss homework, quizzes, exams • Discuss lectures, book • Pick up missed handouts • Any materials science related discussions e

COURSE MATERIAL Webpage: http://ece447.cankaya.edu.tr/ Required text: • Materials Science and Engineering: An Introduction W.D. Callister, Jr., 8th edition, John Wiley and Sons, Inc. (2007). Both book and access to accompanying web-site are needed. Webpage: http://ece447.cankaya.edu.tr/ f

Attendance: 10% Homework: 10% Quiz: 10% Midterm: 30% Final: 40% GRADING Attendance: 10% Homework: 10% Quiz: 10% Midterm: 30% Final: 40% g

Introduction What is materials science? Why should we know about it? Materials drive our society Stone Age Bronze Age Iron Age Now? Silicon Age? Polymer Age? Nano Age?

Four Elements of Materials Science Material trait in terms of the kind and magnitude of response to a specific imposed stimulus. Arrangement of its internal components

Structure, Processing, & Properties • Properties depend on structure ex: hardness vs structure of steel (d) 30 mm 6 00 5 00 (c) 4 mm Data obtained from Figs. 10.30(a) and 10.32 with 4 wt% C composition, and from Fig. 11.14 and associated discussion, Callister & Rethwisch 8e. Micrographs adapted from (a) Fig. 10.19; (b) Fig. 9.30;(c) Fig. 10.33; and (d) Fig. 10.21, Callister & Rethwisch 8e. 4 00 (b) 30 mm (a) 30 mm Hardness (BHN) 3 00 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

Concept Map

THE TRASHCAN I: THE CAN Concept Map Metal Inorganic Crystalline Synthetic

THE TRASHCAN II: THE RUST Concept Map Non-Metal Inorganic Crystalline Naturally Occurring Mineral Crystalline Ceramic

THE TRASHCAN III: THE LINER Concept Map Non-Metal Organic Amorphous Synthetic Polymer

Types of Materials Metals: 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. Metals have high thermal & electrical conductivity because valence electrons are free to roam Ceramics: ionic bonding (refractory) – compounds of metallic & non-metallic elements (oxides, carbides, nitrides, sulfides) Brittle, glassy, elastic Non-conducting (insulators)

ENGINEERED MATERIALS ALLOYS COMPOSITES

SEMICONDUCTORS Solar Cells OLED Technology

Example – Hip Implant BIOMATERIALS With age or certain illnesses joints deteriorate. Particularly those with large loads (such as hip). Adapted from Fig. 22.25, Callister 7e.

Example – Hip Implant Requirements mechanical strength (many cycles) good lubricity biocompatibility Adapted from Fig. 22.24, Callister 7e.

Example – Hip Implant Adapted from Fig. 22.26, Callister 7e.

Hip Implant Key problems to overcome fixation agent to hold acetabular cup cup lubrication material femoral stem – fixing agent (“glue”) must avoid any debris in cup Ball Acetabular Cup and Liner Femoral Stem Adapted from chapter-opening photograph, Chapter 22, Callister 7e.

BIOMIMETICS Some paints and roof tiles have been engineered to be self-cleaning by copying the mechanism from the lotus Lotus leaf surface

Nanotechnology Definition The art and science of building stuff that does stuff at the nanometer scale. R. Smalley, Rice University Nobel Prize Winner Comprised of “nanostructures” or “nanomaterials” that possess at least one dimension that measures approximately less than 100nm AND exhibit novel properties.

Size Comparisons The diameter of your hair is approximately 50,000-100,000 nanometers Your finger nail grows 1 nanometer in 1 second A line of ten hydrogen atoms lined up side by side is 1 nanometer long

Explore the Properties Synthesis of Nanostructures Same Story Explore the Properties Synthesis of Nanostructures Explore/speculate Applications Characterization Testing New processing techniques Controlled structure, size… Reduce cost New applications!!!!!! New Characterization and Testing techniques Better resolution….

SOME CURRENT APPLICATIONS OF NANOTECHNOLOGY 25

SOLAR CELLS Nanotechnology enhancements provide: Improved efficiencies: novel nanomaterials can harness more of the sun’s energy Lower costs: some novel nanomaterials can be made cheaper than alternatives Flexibility: thin film flexible polymers can be manipulated to generate electricity from the sun’s energy

COMPUTING Nanotechnology enhancements provide: Faster processing speeds: miniaturization allows more transistors to be packed on a computer chip More memory: nanosized features on memory chips allow more information to be stored Thermal management solutions for electronics: novel carbon- based nanomaterials carry away heat generated by sensitive electronics

CLOTHING Nanotechnology enhancements provide: Anti-odor properties: silver nanoparticles embedded in textiles kill odor causing bacteria Stain-resistance: nanofiber coatings on textiles stop liquids from penetrating Moisture control: novel nanomaterials on fabrics absorb perspiration and wick it away UV protection: titanium nanoparticles embedded in textiles inhibit UV rays from penetrating through fabric

BATTERIES Nanotechnology enhancements provide: Higher energy storage capacity and quicker recharge: nanoparticles or nanotubes on electrodes provide high surface area and allow more current to flow Longer life: nanoparticles on electrodes prevent electrolytes from degrading so batteries can be recharged over and over A safer alternative: novel nano- enhanced electrodes can be less flammable, costly and toxic than conventional electrodes

SPORTING GOODS AND EQUIPMENT Nanotechnology enhancements provide: Increased strength of materials: novel carbon nanofiber or nanotube-based nanocomposites give the player a stronger swing Lighter weight materials: nanocomposites are typically lighter weight than their macroscale counterparts

CARS Nanotechnology enhancements provide: Increased strength of materials: novel carbon nanofiber or nanotube nanocomposites are used in car bumpers, cargo liners and as step-assists for vans Lighter weight materials: lightweight nanocomposites mean less fuel is used to make the car go Control of surface characteristics: nanoscale thin films can be applied for optical control of glass, water repellency of windshields and to repair of nicks/scratches

FOOD AND BEVERAGE Nanotechnology enhancements provide: Better, more environmentally friendly adhesives for fast food containers Anti-bacterial properties: Nano silver coatings on kitchen tools and counter- tops kill bacteria/microbes Improved barrier properties for carbonated beverages or packaged foods: nanocomposites slow down the flow of gas or water vapor across the container, increasing shelf life

THE ENVIRONMENT Nanotechnology enhancements provide: Improved ability to capture groundwater contaminants: nanoparticles with high surface area are injected into groundwater to bond with contaminants Replacements for toxic materials

SOME FUTURE APPLICATIONS OF NANOTECHNOLOGY 34

BODY ARMOR Nanotechnology enhancements will provide: Stronger materials for better protection: nanocomposites that provide unparalleled strength and impact resistance Flexible materials for more form-fitting wearability: nanoparticle-based materials that act like “liquid armor” Lighter weight materials: nanomaterials typically weigh less than their macroscale counterparts Dynamic control: nanofibers that can be flexed as necessary to provide CPR to soldiers or stiffen to furnish additional protection in the face of danger

DRUG DELIVERY Nanotechnology enhancements will provide: New vehicles for delivery: nanoparticles such as buckyballs or other cage-like structures that carry drugs through the body Targeted delivery: nano vehicles that deliver drugs to specific locations in body Time release: nanostructured material that store medicine in nanosized pockets that release small amounts of drugs over time

CANCER Nanotechnology enhancements will provide: Earlier detection: specialized nanoparticles that target cancer cells only – these nanoparticles can be easily imaged to find small tumors Improved treatments: infrared light that shines on the body is absorbed by the specialized nanoparticles in the cancer cells only, leading to an increased localized temperature that selectively kills the cancer cells but leaves normal cells unharmed

Cells on Patterned VANTA Surfaces @ Bilkent Uni. Erman bengu’s Group Cells on Patterned VANTA Surfaces

SENSORS Nanotechnology enhancements will provide: Higher sensitivity: high surface area of nanostructures that allows for easier detection of chemicals, biological toxins, radiation, disease, etc. Miniaturization: nanoscale fabrication methods that can be used to make smaller sensors that can be hidden and integrated into various objects

NEXT GENERATION COMPUTING Nanotechnology enhancements will provide: The ability to control atomic scale phenomena: quantum or molecular phenomena that can be used to represent data Faster processing speeds Lighter weight and miniaturized computers Increased memory Lower energy consumption

NANOROBOTICS Nanotechnology enhancements will provide: Miniaturized fabrication of complex nanoscale systems: nanorobots that propel through the body and detect/ cure disease or clandestinely enter enemy territory for a specific task Manipulation of tools at very small scales: nanorobots that help doctors perform sensitive surgeries

Carbon Nanotube-based Gears With Benzyne Teeth J. Han, et. al., Nanotechnology, 8, 95, 1997

WATER PURIFICATION Nanotechnology enhancements will provide: Easier contamination removal: filters made of nanofibers that can remove small contaminants Improved desalination methods: nanoparticle or nanotube membranes that allow only pure water to pass through Lower costs Lower energy use

MORE ENERGY/ENVIRONMENT APPLICATIONS… Nanotechnology enhancements will provide: Improvements to solar cells Improvements to batteries Improvements to fuel cells Improvements to hydrogen storage CO2 emission reduction: nanomaterials that do a better job removing CO2 from power plant exhaust Stronger, more efficient power transmission cables: synthesized with nanomaterials

CHAPTER 1: MATERIALS SCIENCE & ENGINEERING Materials are... engineered structures...not blackboxes! Structure...has many dimensions... Structural feature Dimension (m) -10 atomic bonding < 10 -10 missing/extra atoms 10 crystals (ordered atoms) -8 -1 10 -10 second phase particles -8 -4 10 -10 crystal texturing -6 > 10 1

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, sintering, vapor deposition, doping forming, joining, annealing.

ELECTRICAL • Electrical Resistivity of Copper: Resistivity, r T (ºC) -200 -100 Cu + 3.32 at%Ni Cu + 2.16 at%Ni deformed Cu + 1.12 at%Ni 1 2 3 4 5 6 Resistivity, r (10-8 Ohm-m) Cu + 1.12 at%Ni “Pure” Cu Adapted from Fig. 18.8, Callister & Rethwisch 8e. (Fig. 18.8 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.) • Adding “impurity” atoms to Cu increases resistivity. • Deforming Cu increases resistivity.

OPTICAL • Transmittance: -- Aluminum oxide may be transparent, translucent, or opaque depending on the material structure. single crystal polycrystal: low porosity high porosity Adapted from Fig. 1.2, Callister & Rethwisch 8e. (Specimen preparation, P.A. Lessing; photo by S. Tanner.)

DETERIORATIVE • Stress & Saltwater... • Heat treatment: slows -- causes cracks! • Heat treatment: slows crack speed in salt water! “held at 160ºC for 1 hr before testing” increasing load crack speed (m/s) “as-is” 10 -10 -8 Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC Adapted from Fig. 11.20(b), R.W. Hertzberg, "Deformation and Fracture Mechanics of Engineering Materials" (4th ed.), p. 505, John Wiley and Sons, 1996. (Original source: Markus O. Speidel, Brown Boveri Co.) Adapted from chapter-opening photograph, Chapter 16, Callister & Rethwisch 3e. (from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.) 4 mm -- material: 7150-T651 Al "alloy" (Zn,Cu,Mg,Zr) Adapted from Fig. 11.26, Callister & Rethwisch 8e. (Provided courtesy of G.H. Narayanan and A.G. Miller, Boeing Commercial Airplane Company.)

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.