Answer the following in complete sentences: 1.How is controlling light useful to humans? Provide 2 examples in your answer. 2.What are two biotechnologies that have positively impacted your life? April 29, 2008 DRILL U3h – L2

The technology of producing, altering, and combining materials. Example applications: Producing paper from wood, Producing aluminum from ore, Drilling holes in wood, Annealing to soften metal, Laminating wood. Materials Technology

U3h – L2 “Since the birth of materials science and engineering, materials researchers have consistently improved materials that have, in turn, enhanced the performance of the technologies that used them.” Ivan Amato, Stuff: The Materials The World Is Made Of Materials Technology

What are some examples of improved materials that have enhanced the performance of technology? 1. Aluminum baseball bats 2. Vinyl siding on houses 3. Fiberglass auto-body parts 4. Plexiglas 5. Bonded polyurethane vehicle structures 6. High strength steels in car frames 7. Advanced alloys in airplane engines 8. Polymer composites in airplane wings 9. Chromium steel alloy bicycle frame U3h – L2

Materials Technology What are materials? Everywhere we look we see products made from materials. 1.The walls around us 2.The floor beneath us 3.The pen/pencils in our hands 4.The paper in our notebook 5.The clothing on us U3h – L2

Materials Technology Three categories of materials: (Remember from looooong ago…) 1.Natural – found in nature 2.Synthetic – human-made 3.Composite – Mixture of both U3h – L2

Product Performance – the physical properties of a material are a basic reason for selecting the material Mechanical: tensile strength, fracture toughness, fatigue strength, creep strength, hardness, etc. Electrical: conductivity or resistivity… Magnetic: magnetic susceptibility, saturation magnetization… Optical: polarization, capacitance, absorption… Thermal: coefficient of thermal expansion, heat capacity, thermal conductivity… Environment-related: corrosion behavior, wear behavior… Materials Technology

Most products are made from different combinations of the various generic materials: Metals: Normally combinations of "metallic elements" Usually have free electrons Good conductors of heat and electricity Strong but malleable Lustrous (shiny, reflective) look when polished General

Materials Technology Ceramics: Generally compounds between metallic and nonmetallic elements (oxides, nitrides, and carbides) Insulating Resistant to high temperatures and harsh environments

Materials Technology Plastics (or polymers): Organic compounds based upon carbon and hydrogen They have very large molecular structures Low density and are not stable at high temperatures. Derived from living organisms

Materials Technology Semiconductors: Electrical properties intermediate between metallic conductors and ceramic insulators Electrical properties are strongly dependent upon small amounts of impurities.

Materials Technology Composites: More than one material type Fiberglass, a combination of glass and a polymer, is an example Concrete and plywood are other familiar composites Ceramic fibers in metal or polymers

Materials Technology Paying attention to the materials in your life generates an endless stream of fascinating questions: Why is a skyscraper’s frame made of steel and not copper or polyethylene? What is so special about the silicon crystal that it became the foundation of a society-changing electronics revolution? How did humans learn to transform the raw stuff of the wilderness into the wondrous contemporary array of materials? U3h – L2