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Space Filling Geometry and Materials Science & Engineering. Terry A. Ring University of Utah. Materials Science and Engineering. Study of Materials Structure, Properties and Processing Manipulating the Geometry of Atoms. Packing of Spheres in a Box.
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Space Filling Geometry and Materials Science & Engineering Terry A. Ring University of Utah
Materials Science and Engineering • Study of Materials Structure, Properties and Processing • Manipulating the Geometry of Atoms
Packing of Spheres in a Box • Cubic (Percentage Filled 52%) - Iodine, Uranium • Body Centered Cubic (68%) - Iron, Chromium • Face Centered Cubic (74%) - Silicon, Aluminum, Copper • Random Close Packed (61-64%) - glass Cubic BodyCentered Face Centered
Measure Packing Structure by • X-ray diffraction • X-ray Scattering - Sycrotron • Neutron Diffraction • Light Scattering • opal • Photonic Crystals • Optical Semiconductors
Atom Packing • Gives Properties of Material • Changes with Temperature • Higher temperatures less density. • Gives Form to crystals • Different Energy for Different Packings Energy (Kcal/mole)
Packing Defects • Equilibrium Defect Concentration at Temperature • Alters properties of crystal • Color • Ruby - Cr atoms added to Al2O3 • Electrical Conductivity • Mechanical Properties • Strength • Wear
Real Materials • Packing of Mixed Sized Spheres • Packing of Non-Spherical Objects • Packing of Mixtures of Non-Spherical Objects
Real Materials • Monocrystals - Jet engine blades, Silicon Wafer, Watch Crystal • How would you make one? • Poly-Crystals - Iron bar, Ceramic Cup • Two levels of packing • atom packing into crystallites • crystallite packing into microstructure • Composites • Two levels of packing • Two materials • Polymer + Ceramic - Carbon Fiber Epoxy • Metal + ceramic - Al2O3 reinforced Aluminum
Odd Materials • Fullerene • Carbon nanotubes • Fractal Aggregate Structures Stuck Together • Network of Fractal Aggregates