Dent Anatomy Packet #4
Terms
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- Crystalline and Amprphous (can be mixtures)
- What are the two types of nanostructures??
- Polymers
- Carbon based organic compounds, examples being plastics, rubbers, waxes, human soft tissues, silicones. Transparent or opaque, soft weak, flexible and light weight.
- Phase
- a ______ is a region in a material that has a unique composition and/or structure Ex water and ice. (phase/map/grain)
- Reaction:
- composition + processing-----chemical bonding + structure----Properties
- crystalline nanostructures
- There are two types of nanostructures--crystalline and amorphous. This type is made up of lattices and unit cells (the smallest group of atoms of the lattice that can be repeated in all directions to generate the lattice)
- Composite
- Name for mixture of solid materials such as metals, ceramics and polymers
- Hydrocolloids
- Semi-solid material. Mixture of polymer and water. Examples are alginate, jello, moist human soft tissues
- Van der Walls bonding
- type of bonding that is LOW strengh. Seen in polymers and waxes--between the chains
- Network (Thermosetting) polymer structure
- There are three types of polymer structures in Amorphous Nanostructures, 1) LInear (thermoplastic), 2) Network (thermosetting) and Crosslinked, which is a medium strength bond and a hybrid of the first two. Which one DOES NOT soften when heated?
- Metallic bonding
- type of bonding that is "medium strength". Delocalized elecrons shared between all aton nuclei. High thermal conductiviites, high ductility
- They DO NOT have microstructures since they are ususally CLEAR---glass
- there are many materials hidden in microstructures--grains, grain boundaries, phases, etc. What kind of microstructures do purely amorphous materials have?
- Polymorph---ex) carbon-diamond, graphite, glassy carbon
- A nanostructure that has ONE composition with MORE than one nanostructure
- alloy
- A specific name for a mixture of metals such as stell or brass
- compsition, temperature and structures
- Phase diagrams relate ____, ______ and _____.
- A HIGH modulus of elasticity---the less elastic, the HIGHER modulus of elasticity
- Would a metal have a high modulus of elasticity or a low modulus of elasticity??
- composition and structure
- The smallest set of info that we can completely difine a material is ______ and ______.
- Ceramics
- Compound that is BETWEEN a metal nad a non-metal. Examples are porcelain, glass, cement, composites. Are translucent or opaque, non-conductive, and HARD, brittle and stiff. Examples re oxides, nitrides, carbides hydroxides, etc.
- Amorphous
- types of Glass and glassy ceramics, which are noncrystalline and without long range order are an example of Crystalline nanostructures or Amorphous nanostructures?
- Microstructure
- There are two types of internal structures in materials. nanostructures (atom arrangements) need an electron microscope to see. the ______ is visible with a light microscope
- Face Centered cubic (steel is an example of body centered cubic
- There are different types of unit cells in crystalline nanostructures. the most common and energetically favorable one is (Cubic/Face centered cubic/Body Centered Cubic/Hexagonal close packed)
- Thermoplastic (Linear) polymer structure
- ________ polymers (thermoplastic/amorphous) soften when heated, have linear polymer chains composed of long covalently bonded atoms and have WEAK bonding between chains (ex is plastic bag)
- covalent bonding
- this type of bonding is present in ceramics and polymers (covalent/ionic/metallic or vanderwalls)
- composite
- combo of two or more different materials. 3 types based on reinforcing filler size. Examples are fiberglass, reinforced concrete, dental composites, human hard tisssues, or carbon composites
- Ionic bonding
- Ceramics are brittle largely because of this type of bonding (covalent/ionic/metallic/vanderwalls)
- Phase diagram
- Diagram that tells you what structures will be present in a material
- Isotropy---when you stretch out a microstructure, you elongate the grains and give it better properties by causing the grains to form different shapes. THis is known as Anisotropy
- Microstructures have two possible grain patterns---Isotropy and Anisotropy.Which one has properties that are the SAME in all directions?