Transcript Space Filling Geometry and Materials Science & Engineering

Space Filling Geometry and
Materials Science & Engineering
Terry A. Ring
University of Utah
Materials Science and
Engineering
• Study of Materials Structure, Properties and
Processing
Properties
Structure
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
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Angle
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
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 NonSpherical Objects
• Packing of
Mixtures of NonSpherical 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