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  • 1. Looking Inside Materials
    • This topic will help you to complete our coursework presentation before Christmas
    • It will enable you to explain the properties of a material that make it suitable for an application. You will also be able to explain the reasons for these properties at an atomic level…
  • 2. From Chapter 4…
    • We know how:
      • Materials have different properties
      • This means that they behave differently under certain conditions i.e. stress
      • The amount of a material also affects its behaviour. A wire behaves differently than a block of the same material
      • Materials also interact differently with light and electricity
  • 3. Inside Materials
    • How do we see inside materials?
    • We can use optical microscopes…
  • 4. What would we see?
    • Visible structures like the grain of wood, the cells in a plants. This can explain physical characteristics.
  • 5. Atomic Structure
    • Why do ceramic materials break easily but metal only dent when struck with a hammer???
    • We need to know what is different INSIDE the materials on an atomic scale
  • 6. Non-Optical Microscopes
    • In pairs summarise the main features of:
      • Optical Microscopes
      • Scanning Electron Microscopes
      • Atomic Force Microscope
    • Include:
      • The way in which they ‘see’ the image
      • What the image is like
      • How magnification is calculated
  • 7. Magnification
    • Magnification is dependent on
      • Image Size and
      • Specimen Size such that:
      • Magnification = Image Size / Spec. Size
      • What is the magnification of a SEM when the image on the monitor is 10cm and the specimen is 0.5nm?
      • M = 10 x 10 -2 / 0.5 x 10 -9 = 200000000
      • If an atom is 0.1nm, how many fit onto the screen?
        • 0.5nm / 0.1nm = 5
        • Try Scaling Exercise – 20E
  • 8. Types of Structure
    • When a liquid cools it solidifies
    • The resulting solid may have an orderly structure (CRYSTALLINE) or disordered (AMORPHOUS).
    Orderly ‘Crystalline’ Structure Shows some irregularity or ‘Poly-Crystalline’ Structure
  • 9. Crystal Size
    • What affects the size of the crystals in a solid?
  • 10. Cooling and Crystal Size
    • Quick cooling results in _________ crystals
    • Slow cooling results in ________ crystals
    SMALL LARGE