what is not a mechanical property?
thermal conductivity
an amorphous crystal structure has short-range order only.
true
metals are made up of mostly what?
metallic elements
the same material that is processed differently will have the same properties
false
metals are usually what
crystalline
are metals usually single or multi grain?
multi grain
glasses are usually
amorphous
are glasses mutli grain, single grain, or neither?
they are neither
ceramics are usually what
crystalline or a mix of amorphous and crystalline regions
are cermaics single or multi grain?
multi grain
thermoplastics are usually what?
amorphous or a mix of amorphous and crystalline regions
thermosets are usually what?
amorphous
polymers are made up of mostly what?
nonmetallic elements
ceramics are mostly made up of what?
a mix of metallic and nonmetallic elements
Semiconductors are usually what?
crystalline
are semiconductors multi grain or single grain?
single grain
what material type has the highest density?
metals
which material type is least prone to corrosion?
ceramics
Which material type typically has both high strength and ductility?
metals
which material type is the most limited in the temperature that it can operate(high temp)?
polymers
which material type usually has the lowest density?
polymers
which material type has the highest stiffness?
cermamics
which material type has the lowest stiffness?
polymers
which material has the highest thermal conductivity?
metals
which material has the highest electrical conductivity?
metals
which material type can be operated at the highest temperature?
ceramics
which form of SiO2 is transparent?
amorphous SiO2
which form of carbon is the hardest?
diamond
which polymer type is easiest to recycle?
thermoplastics
which polymer is the most brittle?
thermosets
which type of polymer can deform the most without breaking?
elastomers
what is the most common semiconductor?
silicon
the equilibrium spacing between atoms in a solid is the same at all temperatures.
false
it takes a force to move atoms in solids away from their equilibrium.
true
are primary bonds stronger or weaker than secondary bonds?
stronger
the primary bonding type that involves the transfer of electrons from positive to negative ions?
ionic bonding
the primary bonding type that involves sharing of electrons that are not free to move is what?
covalent bonding
the type of bonding that occurs where valence electrons flow freely is what?
metallic bonding
the type of bonding that occurs mostly in metals is what?
metallic bonding
the type of bonding that occurs mostly in ceramics is what?
covalent (ionic or mix of the two)
the type of bonding that occurs mostly in semiconductors is what?
covalent bonding
the type of bonding that occurs mostly in thermoplastics is what?
covalent and secondary bonding
the strength of an elastomer can be increased by?
increasing the number of covalent bonds
are covalent bonds directional?
no
If the bonding energy for MgO is 1000 and the bonding energy for tungsten is 849, what would have the higher melting point?
MgO
If the bonding energy for MgO is 1000 and the bonding energy for tungsten is 849, what would have the higher stiffness?
MgO
the same compound can form a crystalline or an amorphous structure.
true
atoms in solids are not at their equilibrium position near defects?
true
the number of vacancies in a solid decreases as temperature increase.
false
a interstitial solid solution is more likely to occur when the minor element atom is small relative to the major element>
true
a substitutional solid solution is more likely to occur when the minor element (solute) is small relative to the major element (solvent).
false
defects affect the properties of materials.
true
Permanent deformation to a material when loaded is called what?
plastic deformation
if plastic deformation is difficult, ductility is lower.
true
the metal crystal structure with the highest ductility is.
FCC- face centered cubic
the metal crystal structure with the lowest ductility is.
HCP - hexagonal close pack
Dislocation slip is easiest in which metallic crystal structure?
FCC - face centered cubic
is dislocation slip easier in ceramics?
no
which is stronger pure copper or copper with 10weight% zinc?
copper with 10 weight% zinc
which is stronger copper that has not been plastically deformed or plastically deformed copper?
plastically deformed copper
which is stronger pure copper with a small grain size or a large grain size?
pure copper with the small grain size
which is stronger than a single-phase aluminum alloy or an aluminum alloy with precipitates.
the single phase aluminum alloy
the number of vacancies increases with increasing temperature.
true
dislocation slip occurs along random direction in a crystal.
false
plastic deformation occurs by bonds breaking and reforming?
true
will a thermoplastic rope that has been formed with plastic deformation be stronger if it has been deformed?
with plastic deformation