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Materials

Materials. “Materials can effectively generate and capture students’ interest in science, mathematics, engineering, and technology.” -Dr. Thomas Strobe University of Washington. Why Study Materials?. Materials in bulletproof vests worn by Police

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Materials

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  1. Materials

  2. “Materials can effectively generate and capture students’ interest in science, mathematics, engineering, and technology.” -Dr. Thomas Strobe University of Washington

  3. Why Study Materials? • Materials in bulletproof vests worn by Police • Warm, lightweight, waterproof winter coats • Materials have played a significant role in field of engineering and education http://www.alpineco.com/bulletproofvests.htm

  4. FYI • Interesting points about advanced materials • Markets for advanced ceramics grew from less than $2 billion in 1987 to over $20 billion in 2000 • Materials consume up to 50% of manufactured goods cost • According to U.S. Office of Technology, a key to remaining competitive in the world is to train more scientists and technologists with a broad background in advanced materials

  5. History of Materials Science • Babylonians first makers of ceramic building materials • Imprinted clay tablets used to teach trades from parents to offspring in 2200 B.C. • Time periods named after dominantly-used material http://www.livius.org/zo-zz/zopyrus/zopyrus.html

  6. Time Periods 8000 B.C. - Hammered Copper 7000 B.C. - Clay Pottery 6000 B.C. - Silk Production 5000 B.C. - Glass Making 4000 B.C. - Smelted Copper (Bronze Age) 1000 B.C. - Iron Age 500 B.C. - Cast Iron 300 B.C. - Glass Blowing 105 A.D. - Paper

  7. Time Periods 600 - 900 - Porcelain 1540 - First Foundries 1774 - Crude Steel 1789 - Discovery of Titanium 1800 - Battery 1824 - Portland Cement 1850 - Reinforced Concrete 1856 - Bessemer Steel-making Process 1870 - Celluloid Production

  8. Time Periods 1871 - Periodic Table 1884 - Nitrocellulose 1886 - Electrolytic Reduction of Aluminum 1891 - Silicon Carbide 1907 - First Totally Synthetic Polymer 1923 - Tungsten Carbide 1930 - Fiberglass 1937 - Nylon 1947 - Germanium Transistor

  9. Time Periods 1950s - Silicon Photovoltaic Cells & Transistors 1958 - Ruby Laser 1959 - Integrated Circuit 1966 - Fiber Optics 1986 - High Temperature Super Conductors Data Courtesy of Dept. of Energy and Energy Concepts, Inc.

  10. New Materials • New materials are designed based on need • Engineers can design without worrying if a material exists for their application

  11. Characteristics of Materials • Strength (Stiffness) • Ability to resist effects of tension, compression, and torsion forces • Ductility • How well a material can be shaped without fracturing • Brittleness • When a material will break while undergoing small deformations

  12. Characteristics of Materials • Hardness • Ability to resist indentation and wear • Elasticity • Ability to return to original shape after deformation • Electrical Conductivity • Ability to conduct electrons/electricity • Thermal Conductivity • Ability to conduct heat

  13. Classifying Materials • Metals • Ceramics • Polymers • Composites

  14. Metals • Earliest used were “native” metals • Copper, Gold, Silver, and Meteoric Iron • Can be classified as Ferrous or Non-Ferrous • Ferrous • Contain 50%+ of iron • Attract magnetic materials • Non-Ferrous • Contain less than 50% iron • Do not attract magnetic materials • Higher corrosion resistance

  15. Metals Mechanical Properties • Strong • Tough • Malleable • Ductile • Most are • Opaque • Lustrous • Dense • Good Heat and Electric Conductors • High Melting Point

  16. Metal Facts • Iron and Steel are 1st and 2nd most commonly used metals • Aluminum is third • Lightweight • Can be stronger than steel

  17. Ceramics • Derived from Greek word - keramos • Burned material • Early applications were building materials and containers • Glass, although considered a ceramic, is a separate part • Lacks crystalline organization • No orderly atomic structure

  18. Ceramics • Clay products • Refractories • Used in high temperature applications • Made of clay • Abrasives • Extremely hard, pure, ceramic compounds or mixtures • Glasses http://skovsantik.dk/keramik+stentøj.htm

  19. Polymers • Formed by Greek words: • Poly - Many • Mer - Parts • Natural Materials • Wood, leather, cotton, wool, silk, rubber • Polymers processed by plants and animals • Proteins, Enzymes, starches, and cellulose • Plastics http://www.hydropolymers.com/en/products/pvc/

  20. Plastics • Polymers and Plastics ARE NOT the same • Plastics are a member of the polymer group • Are Synthetic Polymers • Thermoplastic • Can be reformed • Recyclables • Thermoset • Once set, cannot be softened by heat

  21. More About Polymers • Are not strong • Good electrical insulators • Low melting temperatures

  22. Polyethylene Terephthalate • PETE • Recycle Code - 1 • Most comes from beverage containers • 99% pure, granulated recycled PETE sells half cost of new PETE • Recycled Uses • Fiberfill of jackets, strapping, liquid soap bottles, surfboards, paint brushes, tennis ball fuzz, and more beverage bottles http://www.designinsite.dk/htmsider/mb0011.htm

  23. High-density Polyethylene • HDPE • Recycle Code - 2 • Well-developed process for recycling • Recycled Uses • Drain pipes, flower pots, plastic lumber, trash cans, automotive mud flaps, kitchen drain boards, beverage bottle crates, stadium seats, recycling bins, traffic barrier cones, golf bag liners, and toys http://www.inglass.com/hdpe_bottles.htm

  24. Polyvinyl Chloride or Vinyl • PVC or V • Recycle Code - 3 • Not burned due to release of hazardous fumes • Dioxins and Furans • Recycled Uses • Drainage pipes, pipe fittings, floor tiles, bottles, doormats, hoses, mud flaps Plastic Separating System http://www.labs.nec.co.jp/rel/english/topics/t12.html

  25. Low-density Polyethylene • LDPE • Recycle Code - 4 • Burned in incinerator-powered generators to produce electricity • Recycled Uses in where color is not important • Garbage can liners, grocery bags, paint buckets, fast food trays, lawn mower wheels, and automobile battery parts http://www.pop-international.com/POP/products_plastic.htm

  26. Polypropylene • PP • Recycle Code - 5 • Recycled Uses • License plate holders, desktop accessories, hanging files, food service trays, flower pots, and trash cans http://www.cawalker.co.uk/index.asp?id=43

  27. Polystyrene • PS • Recycle Code - 6 • Most challenging to recycle • Styrofoam cups and packing material made • Some methods for recycling in place • Chemists still looking for more effective ways to recycle huge amounts http://www.lafourmi.be/contenu/produits/decorer/decorer_polystyrene.html

  28. Composites • Combination of two or more constituent materials bonded together in an effort to provide better properties than those of the individual materials • Ubiquitous in recreational equipment • Used extensively in International Space Station and make over 10,000 pounds of each space shuttle

  29. Composite History • Ancient Israelites and Egyptians added straw to bricks to hold them together • Incas used plant fibers to strengthen pottery • The Colosseum (Coliseum) and other ancient Roman structures were held together with cement containing slackened lime and pozzolana (hydraulic cement) • Slackened Lime • Heating lime and crumbling by adding water • Pozzolana • Volcanic ash from Mt. Vesuvius

  30. What consists in a composite? • Reinforcement • Part that provides strength to composite • Shape of a fiber, whisker, or particulate • Matrix • Glue that holds everything together • Boundary in between

  31. Lay Ups • Unidirectional and bidirectional carbon fiber, Kevlar, and plain-weave fiberglass used in lay ups • Composed of consecutive layers of fabric, resin, and sometimes a core material

  32. Form materials on a mold and paint the them on the matrix of resin (epoxy) My Be Difficult to Use, but inexpensive Combined by two different parts Resin Hardner Factory has materials with epoxy matrix pre-impregnated into More expensive Less mess/easy-use Laid Up By Hand vs. Factory

  33. Epoxy Matrix • When mixed, has a specific time to spend in container to be used • “pot life” • Also has prescribed work time based on amount of hardener used • Time available to work with materials by placing and forming into mold/application • Start of hardening process is called “going off” • When matrix “goes off,” little work time remains

  34. Effective Lay Up Procedure 1. Fabric is cut to appropriate size 2. Bag, peel ply, perforated plastic, and bleeder cut to appropriate sizes 3. Mold is prepared with gel coat, mold release and/or wax 4. Correct amount of resin and hardener used 5. Pot life is not compromised 6. Material laid up within appropriate work time

  35. Effective Lay Up Procedure 7. No sections of the lay up are “starved” (without correct amount of matrix or the resin or epoxy) 8. No sections are over filled with matrix 9. Good seal on the vacuum bag (12-15psi) 10. Peel ply is able to be removed with no folds/creases 11. Mold is released from fabric 12. Clean up of work area completed promptly

  36. Industry Support • ASM International (ASMI) • Society for materials engineers and scientists • Dedicated to advancing industry, technology, and applications of metals and materials http://mnasm.org/asmintl.htm

  37. Industry Support • American Ceramic Society (ACerS) • Dedicated to dissemination of scientific, commercial, and educational information about ceramic materials and industry

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