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101 Cards in this Set
- Front
- Back
Stress formula |
F/A |
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Strain Formula |
Lf-Lo / Lo |
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The goal of running afatigue test for a material is to find the stress level below which no fatiguefailure will ever occur. This stress level is called ": |
Endurance Limit |
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Hardness is a measure of a materials resistance to |
penetration |
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Standard measure of testing used to generate stress - strain relationship is called |
tensile testing |
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Philosoph of conducting a materials life cycle assessment is to incorporate the (blank) in to the decision making process for material selections |
Enviromental impact of products |
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After being continuously loaded for a long period of time a material may even fail at a load level below it's yield point, This kind of material behavior or failure mechanism is called |
creep failure
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Noncrystalline materials are also known as_____ material |
Amorphous |
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Which of the following is a non crystalline material |
polymer
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A material is classified as a ductile material if it's percent elongation is greater than ___ percent |
5 percent |
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The mechanical property of |
Van der waals |
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When a material is subjected to ____ loading on a long term basis, it's fatigue strength has to be considered |
cyclical |
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_______ has been utilized to determine whether a material has the ductile to brittle transition property |
impact testing |
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Burning one gallon of gasoline which weighs about 3kg will emit about 9kg of CO2 |
9kg (*3) |
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MPa is a unit for |
Stress or Strength |
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For an Aluminum product how much energy can be saved using recycled aluminum instead of freshly made aluminum |
95 percent |
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Which of the following has the highest embodied energy |
Device Grade Silicon / Aluminum Alloys |
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Diameter of most atoms falls within the range |
1X10_-10 to 5x10 -10 |
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When a material possesses identical material properties along all directions it is called a ______ material |
Crystalline |
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What are two crystalline materials that are used in industry and what are their applications |
Diamond single crystals are used as abrasives Silicon wafers are used in computer chips |
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LED |
Light Emitting Diode |
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CFL |
Compact Fluorescent Lamp |
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ABS |
Acrylonitrile Butadiene Styrene |
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HDPE |
High Density Polythylene |
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PA |
Polyamide |
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PC |
Polycarbonate |
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PET |
Polyethelyne Terephthalate |
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PMMA |
Poly(Methyl Methacrylate) |
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POM |
Polyoxymethylene |
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PP |
Polypropylene |
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PVC |
Polyvinyl Chloride |
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UHMWPE |
Ultra High molecular weight Polyethylene |
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GFRP |
Glass Fiber Reinforce Plastic / polymer |
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GHG |
Green house gasses |
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CFV |
Carbon Footprint Verification |
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S-N Diagram |
Stress vs number of loads cycles |
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HR |
Rockwell Hardness |
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HB |
Brinell Hardness |
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HV |
Vickers Hardness |
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STM |
Scanning Tunneling Microscopy |
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RoHS |
Restriction of Hazardous Substances |
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LCA |
Life Cycle Assesment |
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TEM |
Transmission Electron Microscopy |
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STM |
Scanning tunneling Microscopy |
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BCC |
Body Centered Cubic |
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FCC |
Face centered Cubic |
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CNT |
Carbon nanotube |
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What are unicell structure |
BCC and FCC and HCP |
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What is creep? |
deformation from constant load below the yield strength |
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Fatigue |
When a material is subjected to cyclical loading |
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Toughness |
The Amount of energy that a material can absorb per unit volume before rupture |
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What is hardness? |
The materials resistance to penetration |
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What are the 5 material properties |
Strength, Elasticity, Hardness, toughness, ductility |
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Metals |
Ferrous and nonferrous |
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Polymer |
plastic and rubber |
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Ceramics |
Glass, cement |
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Composite |
Fiber / resin, concrete, plywood |
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Semi conductors |
Computer chip |
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Embodied Energy |
Energy required to produce materials from ores or feedstocks |
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Why are auto tires all black in color |
Carbon blended rubber |
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What is the typical material used for the structures of new generation aircrafts |
Composite and aluminum |
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Toilet bowl is made of |
Porcelain ceramics and slip mold casting |
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How much energy can be saved by replacing incandescent bulb with LED |
76 percent energy saved |
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How are Solar panels made and how do they work? |
They are semiconductors |
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How much CO2 will be realeased to the atmosphere from burning 1 gallon of gas |
9.07 kg |
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How do we make our living environment sustainable? |
implement LCA (Life cycle awareness) |
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Why recycle materials? |
Aluminum-95 percent less energy
Steel - 33 percent Paper - 40 percentplastic -90 glass-30 |
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Carbon footprint |
Total amount of GHG emissions caused directly and indirectly by an individual organization event or product |
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Top greenhouse gas? |
Carbon Dioxide |
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Fossil fuels create ___ percent of co2 emission |
95 |
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Mechanical behavior testing |
Tensile - elastic modulus, stiffness, ductility Impact test- energy required to fracture a material hardness test - hardness wear and tear |
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Thermal behavior |
conductivity, heat capactiy, expansion, and melting temp |
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Magnetic |
Electrical, optical and corrosion |
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What are the typical mechanical properties |
Elastic modulus, strength, ductility, Hardness, toughness, creep resistance, Visco elasticity |
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______ : sigma = E * epsilon Where E is the modulus of elasticity |
Hookes law |
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Stiffness is the opposite of? |
Elasticity so use elastic modulus |
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Deflection is |
The shape and stiffness of a beam determine the amount of deflection for a given load |
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Shear Stress is |
Sheer modulus * Shear strain = G concerns with the deformation of a solid when it experiences a force parallel to one of its surfaces while it's opposite face experiences an opposite force |
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Ductility is equal to |
Percent elongation at fraction = (Lf-Lo)/Lo * 100 percent Greater than 5 percent = ductile, less than 5 percent = Brittle |
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Modulus of toughness is equal to |
the total area under the stress strain curve at the point of rupture |
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Viscoelasticity |
Propertyy of materials that experience both liquid and solid characteristics when underghoing deformation
|
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Rheology is the study of |
viscoelasticity |
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Metallic bonds |
sea of free valence electrons |
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Covalent bonds |
sharing of valence electrons |
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Ionic bonds |
Between cations and anions |
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Physical bonds |
Van der waal bonds |
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Weakest link theory |
Plastic is as weak as the weakest bond in it |
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Crystalline solids are formed by |
stacking of atoms in a specific fashion |
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Polymer are made up of what bonds |
Covalent and secondary bonds |
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Crystals bonds |
Semiconductors (covalent bonds)
Ceramics covalent and ionic bonds Metals - metallic bonds |
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Crystal is |
solid with the atoms or molecules or ions are packed in a regularly ordered repeating pattern in all 3 dimensions |
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Lattice |
Imaginary skeleton of a crystal structure |
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Unit cell |
Subdivision of a lattice that still remains the overall characteristics of the entire lattice |
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Elements or materials that exist in mor ethan one crystal structure are called |
Allotropic |
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Crystal impurity |
results in a solid solution, not really a bad things, affects clarity of a diamond |
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Structural defects (4 classes) |
Vacancies and interstatial points Dislocations (1d line) Grain boundaries (2 d planar) Noncrystalline or amorphous (3d) |
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Substitutional Solid Solutions |
Solute is too big to fit in the cracks so replaces the solvent |
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Interstatial Solid Solutions |
Small enough to fit in the cracks, i.e Steel Alloys |
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Dislocation |
When a material is above it's yield strength dislocation motion occurs by sequential bonds breaking and forming. Mechnism for permanent or plastic deformation of materials |
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Grain boundaries occur in |
all polycrystalline materials (metals and ceramics) |
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Polycrystals info |
Most engineering materials are polycrystals or poly crystalline |