1. Introduction to Materials © 2012 Project Lead The Way, Inc.Principles of Engineering

2. What we will learn 1. How does an engineer predict the performance and safety for a selected material? 2. What are the advantages and disadvantages of utilizing synthetic materials designed by engineers? 3. What ethical issues pertain to engineers designing synthetic materials? 4. What did you learn about the significance of selecting materials for product design? 5. How can an existing product be changed to incorporate different processes to make it less expensive and provide better performance? 6. How does an engineer decide which manufacturing process to use for a given material? 7. How do the recycling codes and symbols differ from state to state? 2

3. What Are Materials? Currently the MatWeb Material Property Data website lists over 76,000 individually unique materials Substances out of which all things are made What materials are present in the classroom? http://www.matweb.com 3

4. Material History Throughout history cultures have been defined by their ability to select and modify materials. Can you think of a time in America when material availability played a critical role in defining culture? Is American culture currently being defined by availability and demand for materials? 4

5. Material History Advancements in materials, technology, and science create continued advancement possibilities for each sector. Materials continue to change the world. Technology Advancements Science Advancements Materials Advancements 5

6. Material Composition Consist of only one type of particle or atom Cannot be broken down Criteria for element classification Based on individual properties Grouped according to shared properties Amount of substance is irrelevant Elements What makes a material? 6

7. Material Composition Physical Properties – Boiling point, melting point, density, color, hardness, and texture Chemical Properties – Reactivity to acid, oxygen, and flammability Classification of Elements Elements Metals NonmetalsMetalloids Divided into three categories based on 7

8. Material Composition Metal Elements Good conductors of heat and electricity, hard, shiny, reflect light, malleable, ductile, typically have one to three valence electrons Distinguishing Characteristics 8

9. Material Composition Nonmetal Elements Most are gases at room temperature Solids are dull, brittle, and powdery; electrons are tightly attracted and restricted to one atom; poor conductors of heat and electricity Distinguishing Characteristics 9

10. Material Composition Metalloids Possess both metallic and nonmetallic properties Distinguishing Characteristics 10

11. Material Composition Compounds are created when two or more elements are chemically combined Compounds Properties are different than the elements from which the compound was created Most substances are compounds 11

12. Material Composition Element combinations are not random but based upon specific mass ratios, such as H 2 O = 1 g of hydrogen to 8 g of oxygen Compounds Compounds can only be broken down through chemical processes, not physical processes 12

13. Material Composition Elements within the mixture retain their identity Mixtures Non-chemical combination of any two or more substances Mixtures can be physically separated Mixtures do not have a definite ratio 13

14. Material Classification Metallic Materials Ceramic Materials Organic Materials Polymeric Materials Composite Materials Based upon material composition and distinguishable properties Common material classification categories: 14

15. Metallic Materials Pure metal elements (Not commonly found or used) Thermal and electrical conductors Mechanical properties include strength and plasticity Metal element compounds (alloy) (Commonly used due to the engineered properties of the compound) Distinguishing Characteristics 15

16. Compounds consisting of metal and nonmetal elements Thermal and electrical insulators Mechanical properties include high strength at high temperatures and brittleness Ceramic Materials Distinguishing Characteristics 16

17. Ceramic Materials Applications Clay—Shaped, dried, and fired inorganic material Examples: Brick, tile, sewer pipe, chimney flue, china, porcelain, etc. Refractory—Designed to provide acceptable mechanical or chemical properties while at high temperatures Example: Space shuttle all- silica insulating tiles 17

18. Ceramic Materials Applications Rectifiers—Allow current to flow in one direction Heating elements for furnaces Electrical Resistors—Create desired voltage drops and limit current Thermistors—Application of heat regulates current flow 18

19. Are or were once living organisms Consist of mostly carbon and hydrogen Renewable Genetically alterable Organic Materials Distinguishing Characteristics Sustainable 19

20. Compounds consist of mostly organic elements Low density Mechanical properties include flexibility and elasticity Polymeric Materials Distinguishing Characteristics Polymeric Subgroups Plastics Elastomers 20

21. Plastics Polymeric Materials Formed into a desired shape by applying heat and pressure and being cooled Thermoplastic May be heated and remolded Thermosetting Formed into a desired shape by applying heat and pressure and being cooled May not be heated and remolded 21

22. Elastomers Polymeric Materials Can be stretched 200 percent of their length at room temperature and can return quickly to original length after force is released Natural or synthetic material Vulcanization Chemical process used to form strong bonds between adjacent polymers to produce a tough, strong, hard rubber (automobile tires) 22

23. Composite Materials Composed of more than one material Designed to obtain desirable properties from each individual material Distinguishing Characteristics 23

24. Composite Materials Layer Composites— Alternate layers of materials bonded together Particulate Composites— Discrete particles of one material surrounded by a matrix of another material Fiber-Reinforced Composites— Composed of continuous or discontinuous fibers embedded in a matrix of another material 24

25. Material Selection Material selection is based upon application, required material properties, and budget. Initial material property considerations consist of product function, environmental conditions, and material degradation. Applications can vary from electrical components to construction of large-scale civil engineering projects. 25

26. Refined material selection based upon: Technical and structural analysis Examination of known and desired properties, such as: Material Selection Mechanical Thermal Electromagnetic Chemical 26

27. Mechanical Properties Deformation and fracture as a response to applied mechanical forces Material Selection Strength Hardness Ductility Stiffness 27

28. Thermal Properties Affected by heat fluxes and temperature changes Material Selection Thermal Capacity—Heat storage capacity of a material Thermal Conductivity—Capacity of a material to transport heat Thermal Expansion—How a material expands or contracts if the temperature is raised or lowered 28

29. Electrical Properties Material response to electromagnetic fields Material Selection Electrical Conductivity—Insulators, dielectrics, semiconductors, semimetals, conductors, superconductors Thermoelectric—Electrical stimuli provoke thermo responses; thermo stimuli provoke electrical responses 29

30. Chemical Properties Response and impact of environment on material structures Material Selection Oxidation and Reduction—Occur in corrosion and combustion Toxicity—The damaging effect a material has on other materials Flammability—The ability of a material to ignite and combust 30

31. Alternative Material Selection— Alternative Material selection and development is currently focused on alternative materials. Alternative materials are being designed to solve socioeconomic problems such as sustained economic development and depletion of natural resources. Fullerenes Liquid Crystals Biocompatible Materials Microelectronics Alternative materials include 31

32. The head of a claw hammer The exterior of a file cabinet The doorknob of a classroom door Staples for the classroom stapler A frying pan or stew pot A wristwatch case A standard open-end wrench A socket wrench used to remove spark plugs 32

33. The frame of a bike (various types will consist of different materials) – mountain bike, child’s bike, exercise bike The exterior case of a desktop computer The deck of a lawnmower The blade of a straight-edge screwdriver Forks and spoons The base plate of a clothes iron Coins 33

34. Keys for a house lock A soda container A baby car seat frame A water rocket nozzle or nosecone 34