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99 Cards in this Set

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What are the three main classes of materials?
(1) Metallic
(2) Polymer (plastic)
(3) Ceramic materials
What are the two secondary classes of materials?
(a) composite materials
(b) electronic materials
What are the main properties of metallic material? (type, bond, atomic structure)
a. inorganic
b. metal
c. orderly crystaline structure
d. thermal and electric conductors
e. strong, tough
f. deformable but flexible
g. reflective
h: BOND: metallic
What are five example metallic materials?
1. iron (fe)
2. copper (Cu)
3. aluminum (Al)
4. nickel (Ni)
5. titanium (Ti)
How do metals conduct electricity?
In a metallic bond, electrons are shared in a delocalized manner. Thus one electron jump will cause a domino reaction. Thus electric flow; Current (I).
What are the main properties of polymeric material? (type, bond, atomic structure)
- organic (carbon containing)
- long molecular chains
- non-crystaline structure (mostly)
- poor conductors
- good insulators
- low densities
- low softening / decomposition
- BOND by: VDW
What are the main properties of Ceramic materials? (type, bond, atomic structure, how made)
- organic (carbon containing)
- metallic and non-metallic material ionically bound together
- structure: crystaline, non-crystaline, or both
- physical: hard, high temp, brittle
- (also: light, strong, hard, heat-resistant)
- usually made by: SINTERING
How are ceramic materials bonded?
Ionic bonding
What is the atomic structure of ceramic materials?
structure: crystaline, non-crystaline, or both
How are ceramic materials usually made?
Sintering
What is the molecule for glass?
SiO2 - Silica
What are the defining properties of glass?
- transparent
- supercooled liquid (acts like solid)
- electrically insulating
- brittle
What is an example of a Semi-Conducting material?
Si - Silicone
What is the main property of a Semi-conductor?
electrical resistivity
How are semiconductors mainly used? (list three)
(main) integrated circuits
(others:)
- LED's
- solid state lasers
- MOS (Metal Oxide Silicon) technology
What is a SUPERconductor?
a material that - below a critical temperature, will pass an electrical current with Zero resistance
What are examples of Superconductors?
- Nb3Sn (25k)
- YBa2Cu3O4 (90k)
What is a COMPOSITE material? What are the main physical properties?
- combined material.
- Solid enough to hold together, loose enough to provide gaps.
- High strength:weight ratio
List one main example of a composite material.
Fiberglass (graphite fibers + epoxy)
- use in: a graphite golf club
What is a natural composite material? eg.?
- fibers bound by natural glue
- bone, wood, teeth
What type of material is Polyethylene?
Plastic / polymer
How are metals/metallic alloys fabricated?
- Casting: L -> S
- Rolling: S -> S
- Forging: S ->S
Give examples of cast materials:
- ice (H20)
- iron (Fe)
- many metals
Give an example of a rolled material:
- Al
How are ceramics made?
Sintering (firing)

S->S
How is glass made?
L-> S
Describe the sintering process:
A ceramic process in which powder particles are packed into a mold and heated to a high temperature (~1500 K)

s > s
describe sputtering:
bombarding a "target" surface in a vacuum with atoms or ions to build material up

s > v > s
describe rolling:
send material through press until it things / "rolls out" enough.

eg: Al foil

s > s
describe casting:
pour liquid into mold till it solidifies

L > S
describe chemical vapor deposition
a thin film deposition technique in which reactions in the gas phase create products which then deposit on a substrate

v > s
what is injection molding?
a polymer process by which hot plastic is forced into cavity/mold where it cools into solid

l > s
what is electron-beam evaporation?
a vapor deposition technique in which the source material is heated by means of an impinging electron beam to a sufficiently high temperature that it evaporates

s > v > s
describe the Czochralski Method:
Used to create large silicon boules (long cylinders) from which single crystal silicon wafers are cut.

Basically - dip a single crystal into liquid Si while spinning it until you have a pure boule

L > S
what is Vapor-Liquid-Solid growth?
a method to grow a semiconductor nanowire from an appropriate gas by way of a liquid droplet.

v>l>s
how is fiberglass composite material made?
embedding glass fibers in epoxy

l > s
how are silicone wafers made?
Czochralski method
how are semiconductor nanowires formed?
vapor - liquid - solid growth
What process makes Co layers for harddrives?
sputtering
how are semi-conductors and thin films often made?
Chemical deposition process.

v>s

via hole
Si(4)HCl(4) is made by what process?
chemical vapor deposition
What are 4 types of nano materials? Try to give examples
1. nano particles
2. nano tubes (carbon nanotubes)
3. nano wires (Si, Germanium Ge)
4. nano ribbons
Describe properties of "fumed silica"
- Fe(NoO3)*9H20
- Heat to 900 degrees c in Ch4
- Fe Nanopart
Describe Cobalt nanoparticle
- CoNO3*6420
- heat to 900 C in CH4
- Co nanopart
Name three types of nanotubes
- CH(4)
- C(2)H(2)
- C(2)H(6)
*all different carbon and hydrogen combination
How do you grow a nanotube?
- add metal catalyst with New Particles
- can grow either up or downwards
- start with one seed crystal
What are two most impt. examples of nanowire materials?
Si, Ge
both are semiconductors
- SiH4
- GeH4
How are nanowires made?
- put nano particles on magnetic substrate
- let them grow
def: Anion
Negatively charges ion, they have an extra electron.
how do anions function in relation to other ions?
as anions are negatively charged, they can affect other ions by dispelling their extra electron and thus changing the whole environment's electric landscape
def: Cation
positively charged ion.
has lost an electron.
Do not let alkaline metals touch ____
Salt. Or noble gases. They will mess up the following materials:
- boron
- Al
- Galium
def: Ionic Bond
bond between positively and negatively charged ions

- transfers electrons - coulombic charge
def: covalent bond
materials bound together because they share an electron
examples of a covalent bond?
- diamond
- semi-conductors Si, Ge
- methane: (CH4) Bonds withing molecule are strong
def: metallic bond
-makes rows, orderly, 3-D crystals
-sharing of electrons in delocalized manner
-non-directional
What are the 2 types of secondary bonds?
1) Van derWaals Force
2) Hydrogen Bonds
Van der Waals Force (def)
Def: at any given time there are more electrons on one side of the proton than the other side - so there is thus a momentary attraction.

Weak force, but important
Examples of Van der Waals force in action
1) Gecko Feet
2) PVC (Polyvinyl chloride)
3) Dry Ice (CO2)
4) Polyethylene, PET
5) ALL PLASTICS
What is the bonding type for all "poly"/ platic materials?
VDW
What is the bonding for all ceramic materials?
Ionic
What is the eqn for interaction energy?
V = -A/a^m + B/a^n
What is an expression for the force between atoms?
- The derivative of V(t)
- d/da(-A^-m+Ba^-n)
= mA/a^(m+1) - nB/a^(n+1)
Example of Close-packed structure
metallic structure
(2) Examples of ionic bonding:
- MgO - magnesium Oxide
- Al203 - Aluminum oxide
(6) examples of covalently bonded materials:
- Si - silicone
- Ge - germanium
- GaN - galium nitrate
- AlN - aluminum nitrate
- AlP - Alkaline Phosphate
(4) examples of metallically bonded materials
Al - aluminum
W -- ?
(1) example of a hydrogen bond
H20 - water
What is the atomic layering sequence present in FCC structure?
ABCABCABC
What is the atomic layering sequence present in HCP structure?
ABABABAB
Which atomic structures are close-packed?
FCC - face centered cubic
and
HCP - Hexagonal Close Packed
Which is "loose"
BCC - body centered cubic
How do you calculate Atomic Packing Factor?
APF = volume of atoms in unit cell/volume of unit cell
radius to cube length (a) ratio for BCC:
a=4R/3^.5
radius to cube length (a) ratio for FCC:
a=4R/2^.5
APF for BCC:
APF = .68 (less dense)
APF for FCC
APF = .74 (more dense)
What type of material structure does ALUMINUM have?
(bcc/fcc/hcp)
FCC
What type of material structure does COPPER have?
(bcc/fcc/hcp)
FCC
What type of material structure does LEAD have?
(bcc/fcc/hcp)
FCC
What type of material structure does NICKEL have?
(bcc/fcc/hcp)
FCC
What type of material structure does CHROMIUM have?
(bcc/fcc/hcp)
BCC
What type of material structure does IRON have?
(bcc/fcc/hcp)
BCC
What type of material structure does SODIUM have?
(bcc/fcc/hcp)
BCC
What type of material structure does TUNGSTEN have?
(bcc/fcc/hcp)
BCC
What type of material structure does CADMIUM have?
(bcc/fcc/hcp)
HCP
What type of material structure does ZINC have?
(bcc/fcc/hcp)
HCP
What type of material structure does MAGNESIUM have?
(bcc/fcc/hcp)
HCP
What type of material structure does TITANIUM have?
(bcc/fcc/hcp)
HCP
What happens with an allotropic material? Give an example
It contracts from BCC to FCC structure with temperature

example: iron Fe
What is an example of a material that changes from HCP > FCC?
Cobalt, when temperatures are greater thatn 447C
Main geometric attributes of HCP structure:

(how many bonds between particles?)
- formed by close packed bonds
- 6 bonds per atom in each plane
- 12 bonds/atom
What type of material structure does Silver (Ag) have?
(bcc/fcc/hcp)
fcc
What type of material structure does gold (Au) have?
(bcc/fcc/hcp)
fcc
What type of material structure does Palladium (Pd) have?
(bcc/fcc/hcp)
fcc
What type of material structure does Platinum (Pt) have?
(bcc/fcc/hcp)
fcc
height and "a" measure for unit cell of HCP in relation to atomic radius?
a=2R

c "hexagon height"
c=(8/3)^.5 a
Do an FCC unit cell calculation
Density of fcc solid = mass/unitvolume

Al = #atoms/unit cell * unit cells *atomic weight / a

I think ??
APF=
volume occupied by atoms/total volume