Conceptual Questions
The refractory metals have which kind of crystal structure?
BCC
The ability of a material t withstand an impact blow is often referred to as the _____________ of the material
impact toughness
These materials have good electrical and thermal conductivities, relatively high strength, high stiffness, ductility or formability, and shock resistance. These materials are particularly useful for structural or load-bearing applications.
metals and alloys
Which of the following materials may form crystalline solids?
metals, polymers, ceramics
Anodes undergo a(n) ________ reaction, while cathodes undergo a(n) ___________ reaction in electroplating.
oxidation, reduction
In materials containing vacancies, atoms move from one lattice position to another. This process is known as _________
self-diffusion
The typical electrical conductivity value/range for material are:
semiconductor 10^-6 to 10^4 metals 10^7 insulator 10^-20 to 10^-10
Which of the following choices includes the names for all three cubic crystal Bravais lattices?
simple cubic, face-centered cubic, body-centered cubic
The process by which plastic deformation is produced by dislocation motion is called _________.
slip
Dislocations are defects that are responsible for plastic deformation in crystalline solids. Which of the following correspond to the name of the process by which dislocations move in crystalline solids?
slip, glide
If the Pilling-Bedworth ratio is less than one, the oxide occupies a volume __________ than the metal from which it formed
smaller
The solvent is an element or compound that is present in ___________
the greatest amount
The solvent is an element or compound that is present in ______________
the greatest amount
Atoms are:
the smallest unit of matter that retains the identity of a substance.
________ conductivity is a measure of the rate at which heat is transferred through a material
thermal
The fluorite structure has a _______ Bravais lattice
FCC
A brittle material typically exhibits substantial plastic deformation with high energy absorption before fracture. Is this true or false?
False
A material with higher magnetic permeability will carry magnetic flux less readily than one with lower magnetic permeability
False
Age-hardenable alloy properties depend only on aging time and not on aging temperatures
False
All alloys are age hardenable
False
Although ceramics can be crystalline or partially crystalline, they are never amorphous.
False
An engineer is designing a plane. There is a choice of aluminum or a composite material. The composite weighs half that of aluminum. Choosing the composite will not affect fuel costs.
False
As we move down column 1A of the Periodic Table, chemical reactivity decreases
False
At low temperatures, it will usually only take a large number of atoms a short time to diffuse to produce a uniform structure
False
Because metals have no energy gap, they require high-energy photons to excite their electrons to higher energy levels.
False
Casting operations are only used for metals that have low ductilities such that hot or cold working would be difficult. Is this true or false?
False
Extrinsic semiconductors are materials with properties that are not controlled by impurities
False
In most cases, increasing the average molecular weight or degree of polymerization of a polymer will cause a decrease in various physical properties of that polymer. These decreasing properties include impact toughness, wear resistance, and melting temperature.
False
In noncrystalline materials, plastic deformation occurs by the motion of dislocations. Is this true or false?
False
It is impossible for a steel structure to simultaneously contain ferrite, pearlite, kainite, and martensite
False
Materials that have predominantly ionic or covalent have many free electrons
False
Phase transformations and fracture stress have no bearing on thermal shock behavior
False
The greater the dielectric constant, the less likely a capacitor can hold its charge.
False
The magnetic properties of iron and other magnetic materials are independent of crystallographic directions
False
The process of progressively breaking and reforming bonds requires far more energy than the energy that would be required to instantaneously break all of the bonds across a slip plane.
False
The ratio of sizes of the ionic radii of anions and cations in a cell has no influence on the matter of packing of that cell
False
The term flaw can be used to refer to atomic level defects such as vacancies or dislocations
False
The valance of an atom is the number of electrons in an atom that do not participate in bonding or in chemical reactions.
False
a charge balance is not always required for every point defect introduced in an ionic solid.
False
heating water to the boiling point breaks the van Der Was bonds and changes water to steam, but breaking covalent bonds requires much lower temperature
False
A metallic material containing permanent and aligned magnetic moments that result from the incomplete cancellation of magnetic spin moments; these are present even in the absence of an external field?
Ferrimagnetism
The following describes which type of magnetism: permanent and aligned magnetic moments that result from the incomplete cancellation of magnetic spin moments; these are present even in the absence of an external field?
Ferrimagnetism
Which of the following phases are typically found in low carbon steel?
Ferrite, Martensite, cementite
Which of the following statements is true?
Fiber-reinforced composites with small diameters and long fiber lengths tend to have better strength
Which of the following micro constituents phases are typically found in low carbon steel?
Pearlite, ferrite
The AISI (American Iron and Steel Institute) and SAE (Society of Automotive Engineers) have an assignment system that uses a four- or five-digit number to identify steel alloys. The first two digits refer to the major alloying elements present. The last two or three digits refer to the __________________
Percent of carbon present in the material
Which of the following is not a criterion for unlimited solubility of an alloy?
The atoms must have a 50% or higher difference in atomic radius size
Select what determines the characteristic color of a metal.
The characteristic color is determined by the distribution of wavelengths of the non absorbed light radiation that is reflected
A eutectic reaction involves which of the following phases?
Two liquid phases and one solid phase
What is the relationship between a Miller index value and its negative value?
The vector represent the same line, but point in opposite directions
Why do we add plasticizers to polymers?
To improve flexibility, to improve toughness
Ceramics are said to be ionocovalent materials. This means that they have both ionic and covalent bond characteristics. For a ceramic that has 75% ionic bonding, the charge carriers can be which of the following?
anions, cations, holes, electrons
In an electrochemical cell, the cathode receives electrons while the ___________ loses electrons
anode
The generic reaction M-> Mn+ + ne- represents a reaction that occurs at a(n) _________
anode
Oxidation occurs at the ________; reduction at the ________
anode, cathode
Oxidation occurs at the _________; reduction at the __________
anode, cathode
Metals located near the bottom of the EMF series are:
anodic, reactive
metals located near the bottom of the galvanic series are:
anodic, reactive
________________ materials are materials where magnetic moments are produced in neighboring dipoles. These dipoles will line up in opposition to one another to produce magnetization.
antiferromagnetic
The mean free path defines the ________ distance between electron collisions
average
A material subjected to an impact blow during service should have a ductile to brittle transition temperature _______ the temperature of the material's surroundings
below
The magnetic field needed to bring an induced magnetized material back to zero is called the ___________ of that material
coercivity
What factors determine the characteristic colors of metals and transparent nonmetals?
color is discerned as a result fo the combination of wavelengths that are transmitted. Color is also determined by the distribution of wavelengths of non-absorbed light radiation that is reflected.
When the temperature of a(n) __________ material increases, brittle fibers with a lower coefficient of thermal expansion than the matrix may be stretched to the breaking point.
composite
_____________ is a reaction that causes the growth of a polymer chain. In this reaction, a relatively small molecule is formed as a result of the polymerization reaction and may involved different monomers as starting or precursor molecules
condensation polymerization
A material demonstrating __________ weakly opposes a magnetic field while a _________ material will experience strong magnetism in a magnetic field.
diamagnetic behavior, feromagnetic
Pure carbon exists as several allotropes. The term allotrope refers to _________
different arrangement of carbon atoms
X-rays that strike certain crystallographic planes at specific angles are reinforced rather than annihilated. This phenomenon is called ___________
diffraction
________ refers to the net flux of any species, such as ions, atoms, electrons, holes, and molecules
diffusion
Glass is a material that hardens and becomes rigid without crystallizing. The two main reasons glass bypasses crystallization are the limited __________ of ions or atoms and the rapid ___________ rate.
diffusion, cooling
In metals, the yield strength decreases rapidly at higher temperatures due to a decreased _________ density and an increase in _________
dislocation, grain size
________ are particularly useful in explaining deformation and strengthening in metallic materials
dislocations
The stresses that cause fatigue are often above the yield strength of the material
false
The _____________ demonstrates how long a part may survive or the maximum allowable loads that can be applied without causing failure.
fatigue test
In Fick's first law the J is the _____, D is the _________ and dc/dx is the _________
flux, diffusivity coefficient, concentration gradient
The term harden ability describes the ease with which steels can _________ in a thick quenched section.
form martensite
Electronegativity is the tendency of an atom to _________ an electron
gain
Oxidation is the process by which an atom ________ to become a cation. Reduction is the process by which an atom ________ and extra electron and becomes an anion.
gives up, acquires
What are the three categories of ceramic materials?
glasses, glass-ceramics, crystalline ceramics
______________ is the most widely used are iron. This iron contains many clusters or eutectic cells of interconnected graphite flakes that cause low strength and ductility.
gray case iron
The thermal conductivities of single crystals are ___________ those of polycrystalline materials
greater than
Name the two general activities that accompany a phase transformation
growth, nucleation
Tempering causes the decomposition of martensite in steels, which in turn causes the strength and _______ of the steel to decrease while the ________ and impact properties are improved.
hardness, ductility
Most materials want to form periodic arrangements. These materials form such configurations in order to maximize _________ stability
thermodynamic
Small angle boundaries formed by edge dislocations are called _______ boundaries. Small angle boundaries formed by screw dislocations are called _______ boundaries
tilt, twist
Fick's second law allows us to determine the concentration of one diffusing species as a function of _______ and __________
time, location
For self-diffusion, the activation energy is equal to the energy needed to create a(n) ________ and to cause the movement of the atom
vacancy
The electrons that occupy the outermost filled shell are called _______ electrons
valance
_______ alloys are formed by plastic deformation and have compositions and microstructures significantly different from casting alloys
wrought
Brass is comprised primarily of copper and _____ while bronze is a copper alloy frequently containing ______
zinc, tin
A solidus line separates which of the following phase fields?
α and L + α
A solidus line separates which of the following phase fields?
α and liquid + α
For a particular crystal structure, the slip direction is that direction in the slip plane having the ____________
highest linear density
What is the typical carbon concentration range for medium-carbon steels?
.25-.6
According to Table 13-1 a material with a designation number of 1060 has a manganese percentage of ______________
.60 - .90
In an extrinsic p-type semiconductor, the concentration of electrons is ___________ the concentration of holes.
less than
Match the type of light transmission with its descriptions (a) transmits light with relatively little absorption (b) transmits light diffusely (c) Is impervious to light transmission
1. Transparent- (a) 2. Translucent- (b) 3. Opaque- (c)
What is the maximum number of electrons with opposing electronic spins allowed per orbital?
2
What is the typical carbon concentration range for cast irons?
3-4.5
Zirconium dioxide (ZrO2), sometimes known as zirconia, is a white crystalline oxide of zirconium. It can be used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. The ionic radius of Zr is .079 nm, and the ionic radius of Cl is .14 nm. What is the coordination number of ZrO2?
6
How many atoms or molecules are there in one moles of a substance?
6.023 x 10^23
A Frenkel defect is composed of which of the following?
A cation interstitial and a cation vacancy
Which material retains its strength better at elevated temperatures?
A dispersion-strengthened composite
Hard magnetic materials display which of the following characteristics?
A relatively large hysteresis loop, magnetization and demagnetization may be achieved using relatively high applied fields
Which of the following characteristics is (are) splayed by hard magnetic materials?
A relatively large hysteresis loop, magnetization and demagnetization require relatively high applied fields
Which of the following materials are considered to be composites?
Bone, concrete, fiberglass
Intergranular and trans granular features are often observed on the fracture surfaces of high strength materials. Which kind of fracture is associated with the inter granular crack propagation mechanism?
Brittle
Which kind of fracture is associated with the inter granular crack propagation mechanism?
Brittle
Metals located near the top of the galvanic series are:
Cathodic, unreactive
Which polymerization technique is generally used to produce cross linked and network polymers?
Condensation polymerization
Dislocations represent one type of defect in a crystal. Dislocations are responsible for plastic deformation. There are different types of dislocations. What are the two fundamental types of dislocation?
Edge, Screw
What are two fundamental types of dislocations?
Edge, screw
For P-type semiconductor, ____________
Electron concentration < hole concentration
For nonmetallic materials, what is the name of the region that lies between the valance and conduction bands?
Energy band gap
A _______________ is a vacancy-interstitial pair formed when an ion jumps from a normal lattice point to an interstitial site and leaves behind a vacancy
Frenkel defect
Magnesium has the _____ crystal structure
HCP
Increased hindering of dislocation motion makes a crystalline material
Harder
Which properties are required for abrasive ceramics?
High temperature stability, high toughness, high wear resistance
Which of the following are not general properties of ceramic materials?
High thermal and electrical conductivity
__________ have good electrical and thermal conductivities, relatively high strength, high stiffness, ductility or formability, and shock resistance. These materials are particularly useful for structural or load-bearing application.
Metals and alloys
Silica refractory ceramics are often used for the containment of slags that are rich in:
MgO, Silica, CaO
As the particle content is increased, how does the strength of a particle-reinforced composite change?
Increases
___________ is a type of molding in which thermoplastics are heated above melting temperature and, using an extruder, are forced into a closed die to produce a molding.
Injection molding
What element is the primary constituent of ferrous alloys?
Iron
Fick's first law is given by the equation __________
J = -D((dc)/(dx))
For an n-type semiconductor, where is the Fermi level located?
Just below the conduction band in the band gap
Which is not a required trait of permanent magnets?
Low coercive field
Whether fatigue or fracture, how does the process proceed leading to failure of the material/structure?
Materials deform and fail due to the pretense of or motion of defects.
Below are shown, for five metals, reduction reactions and standard electrode potential values. Which of these metals is the most reactive?
Na1+ + 1e- > Na -2.924V
Can interstitial atoms ever exhibit unlimited solubility in a metal?
No
Choose the list of metals below in which the tendency to give up electrons increases from left to right.
Oxygen, Silver, Zinc, Lithium
What type of steel contains only residual amounts of alloying elements?
Plain carbon steel
_________ occurs when a stress is removed and the material does not go back to its original shape.
Plastic deformation
___________ refers to irreversible deformation that occurs when the force or stress that caused the deformation is removed
Plastic deformation
_____________ are typically organic materials. They are usually good electrical and thermal insulators and generally hav every good strength-to-weight ratios. They are generally not suitable for high temperature applications.
Polymers
Once a system is at a state of equilibrium, a shift from equilibrium may result if one alters which of the following variables?
Pressure, Composition, Temperature (all of the above)
Once a system is at a state of equilibrium, a shift from equilibrium may result by alteration of which of the following?
Pressure, composition, temperature
The nucleus of an atom contains which of the following particles.
Protons, electrons, neutrons
_________ is the fraction of the incident beam that is reflected. Materials with a higher index of refraction have a ___________ reflectivity than materials with a __________ index.
Reflectivity, higher, lower
Stacking faults are defects that really interfere with the slip process. Which of the following statements best describes a stacking fault.
Represents an error in the stacking sequence of close packed planes resulting in a small region that has a HCP stacking rather than FCC stacking.
For the cubic crystal system, how many atoms are there in a single simple cubic (SC) unit cell? In a face-centered cubic (FCC) unit cell? In a single body-centered cubic (BCC) unit cell?
SC: 1, FCC: 4, BCC: 2
_______ defects are unique to ionically bonded materials
Schottky
Covalent bonds are formed by:
Sharing of valence electrons with opposite spins.
How do thermal conductivities of single crystals and polycrystalline materials compare?
Single crystal conductivity is greater.
What is reflection? What are the two types of reflection? How do they differ?
Specular reflection- light reflected from a smooth surface at a definite angle diffuse reflection- produced by rough surfaces and tend to reflect light in all direction
Which of the following is not an example of van Der Waals interactions?
Stambuli forces
Coordination numbers (CN) refer to:
The number of nearest neighbors surrounding a particular atom or ion
The atomic number characterizes each element and is equivalent to:
The number of protons inside the nucleus of an atom
What is the atomic number of an atom?
The number of protons per atom
The motif (aka basis) refers to:
The objects that are placed on lattice points to build up a crystal structure.
In which of the following phenomena do free electrons play a role: thermal conduction or thermal expansion?
Thermal conduction
Plastics may be which of the following?
Thermoplastic, thermosetting
_________ are composed of long chains of polymers that are tangled and can be easily pulled apart by the application of tensile stress. These can easily be recycled. _________ recomposed of long chains of polymers that are strongly cross-linked to one another. These are difficult to recycle.
Thermoplastics, Thermosetting polymers
How are continuous fibers generally orientated in fiber-reinforced composites?
They are aligned parallel to each other
How does light interact with matter?
Transmitted, absorbed, reflected, and/or scattered.
"Coring," which represents a form of non-equilibrium solidification, results in variations in the composition of a solidifying alloy. Coring occurs because of rapid solidification (I.e., the alloy solidifies faster than fission can occur to equilibrate composition). Is this true or false?
True
Activation energies are lower for interstitial diffusion than for vacancy diffusion
True
Ceramics normally have poor toughness, even if they display high strength, because they have virtually no ductility. These materials show both poor tensile toughness and poor impact toughness.
True
Compared to metals, most ceramics have low coefficients of thermal expansion
True
Covalently bonded materials frequently have complex structures in order to satisfy the directional restraints imposed by the bonding
True
Covalently bonded materials frequently have complex structures in order to satisfy the directional restraints imposed by the bonding.
True
Despite extensive recycling efforts, plastics remain one of the largest components of landfills
True
Ductile materials exhibit substantial plastic deformation and high energy absorption prior to fracture. Is this a true or false statement?
True
Elastomers must have some cross linking? True or False?
True
Fatigue refers to failure of a material that is subjected to cyclic stresses or strains (I.e., cyclic loading). It can even lead to failure it the stresses are below the yield stress of the material. Steels exhibit an endurance limit. Beneath the endurance limit, steels cannot fail via fatigue. Al does not have an endurance limit.
True
Fracture toughness, KIC, is fixed materials parameter. It defines the maximum allowable applied stress for a given flaw size or the maximum allowed flaw size for a given applied stress. This is the most important concept for designers who want to avoid catastrophic fractures of structures and components. If a combination of flaw size and applied stress yields a calculated KIC the is greater than the one specified for the material, the materials and/or structure will fail.
True
Impurity atoms in metals, ceramics, and alloys may form substitutional an interstitial solid
True
In precipitation hardening, the solution heat treatment consists of (1) heating the alloy to a temperature such that all solute atoms are dissolved to form a single-phase solid solution, and (20 quenching to produce non equilibrium supersaturated solid solution. The alloy is then aged at a lower temperature to form uniform distribution of small precipitates. Is this true or false?
True
Metallic materials that have undergone work hardening process increased strength but reduced ductility
True
Nanoidentatoin techniques are important fro deforming free-standing micro and nanoscale structures
True
Nickel and cobalt alloys generally have strong corrosion resistance and high-temperature resistance
True
The Aufbau Principle is a device that helps determine deviations from expected ordering of the energy levels
True
The Peirerls-Nabarro stress is the stress required to move a dislocation from one equilibrium location to another
True
The critical radius (r*) is the minimum size of a crystal that must be formed by atoms clustering together in the liquid before the solid particle is stable and can begin to grow
True
The critical stress needed to initiate plastic deformation is the elastic limit of the material
True
The direction of a Miller index and its multiple are the same
True
The direction of a Miller indices and its multiple are the same.
True
The mechanism of increasing the strength of a material by deformation is known as strain hardening
True
The surface energy of a single crystal depends on the crystallographic orientation with respect to the surface.
True
The surface energy of a single crystal depends on the crystallographic orientation with respect to the surface?
True
Thermal energy is transferred by free electrons and lattice vibrations
True
Transfer of heat in ceramics occurs through lattice vibrations
True
decreasing the number of grains or increasing the grain size of a metallic material causes the strength of the metal to decrease.
True
Materials that can have more than one crystal structure are called polymorphic or allotropic. The term __________ refers to pure elements with more than one crystal structure. The term __________ is used for compounds with more than one crystal structure.
allotropic, polymorphic
A Frenkel defect in an ionic crystal is composed of which of the following?
a cation interstitial and a cation vacancy
For most technologically important metal alloys, the usual state or microstructure is:
a metastable one
An overall electrochemical reaction must consist of at least:
a single reduction reaction and a single oxidation reaction
A binary composition vs. temperature phase diagram for an isomorphous system will be composed of regions that contain which of the following phases and/ or combination of phases?
a) α b) Liquid + α c) Liquid
What are some desirable characteristics of refractory ceramics?
ability to withstand high temperatures, ability to remain unreactive and inert in severe environments, low thermal conductivity
During thermal tempering, a glass piece is heated to a temperature:
above the glass transition temperature, below the softening point
The liquids temperature is the temperature _________ which a material is completely liquid. The solidus temperature is the temperature ______ which the alloy is 100% solid.
above, below
When light interacts with matter is said to be attenuate. Attenuation of light (aka how it interacts) by matter can occur in which of the following ways?
absorption, reflection, scattering, transmission
In the Arrhenius equation C0 is constant, R is the gas constant, T is the absolute temperature (K), and Q is the _________ energy required to cause one mole of atoms or ions to move
activation
A material that exhibits almost no plastic deformation would most likely be classified as _______
brittle
Consider the galvanic series. Please select the group of metals or alloys that may be used to galvanically protect 304 stainless steel in the active state.
cast iron, aluminum alloys, zinc, because this group fo metals is more active than 304.
reduction takes place at the:
cathode
In ionic bonds the atom that contributes an electron and has a positive charge as a result is called the ______________. The atom in ionic bonding that accepts an electron and has a negative charge as a result is called the ______________.
cation, anion
A stoichiometric compound Fe3C is also known as _______ and forms when the solubility of carbon in solid iron exceeded. The lamellar structure of a and Fe3C that develops in the iron-carbon system is called _________
cementite, pearlite
This material is generally an inorganic material, does not conduct heat well and must be heated to very high temperatures before melting. Also, this material is very strong and hard, but also very brittle.
ceramics
____________ are generally inorganic nonmetallic materials that do not conduct heat well and must be heated to very high temperatures before melting. They are very strong and hard, but also very brittle
ceramics
For defects in crystalline ceramics there must be a(n) _________ balance when these defects exist.
charge
Stainless steel incorporates what element that will create an oxidative layer on the steel's surface and prevent rusting
chromium
In insulators and intrinsic semiconductors, what is the name of the region that lies above the energy band gap?
conduction band
The ___________ is the number of atoms touching a particular atom, or the number of nearest neighbors for that particular atom.
coordination number
Bonds that are formed by sharing of valance electrons among two or more atoms are _____________ ?
covalent bonds
Bonds that are formed by the sharing of valence electrons among two or more atoms are __________
covalent bonds
If the temperature of a material exceeds the ________ temperature, the ferromagnetic or ferrimagnetic behavior of the material is no longer observed
curie
Which of the following is not a crystal system for Bravais lattices?
decagonal
The rate of nucleation is low for small undercooling and increases for larger undercooling. The growth rate of the new phase ________ continuously as the undercooling __________
decreases, increases
Thermal shock response is affected by all of the following factors except __________
density
A(n) _________ dislocation is illustrated by slicing partway through a perfect crystal, spreading the crystal apart, and partly filling the cut with an extra half plane of atoms
edge
Crystal structures with ions must have ________
electrical neutrality
Crystal structures with ions must have/exhibit
electrical neutrality
__________ structure influences how atoms are bonded together
electronic
The charge carriers in ionic ceramics can be
electrons, holes, anions, cations (all of the above)
cast irons are iron-carbon-silicon alloys that pass through the ________ reaction during solidification
eutectic
The time-temperature-transformation (TTT) diagram from Figure 12-20 is used to predict the _________ treatment required to obtain certain transformations of steel
heat
Materials with high melting points tend to have ________ elastic moduli
high
What are some desirable characteristics of aluminum?
high specific strength, high corrosion resistance, high thermal conductivity
What are some desirable characteristics of aluminum?
high strength, high corrosion resistance, high thermal conductivity, high specific strengths
Superalloys are alloys with attributes of ______ strength at elevated temperatures and resistance to creep at temperatures up to _______
high, 1000
Materials with high bonding energy have also have ________ strength and ____________ melting temperature.
high, high
BCC metals tend to have _________ and __________ compared to FCC metals
higher strengths, lower ductilities
During plastic deformation of crystalline solids, dislocation move on a slip system. A slip system consists of a particular direction and a particular plane. We call them the slip direction and the slip plane. In terms of linear density, does the slip plane have the highest or lowest linear density?
highest
In general, as the impurity concentration (in old solution) of a metal is increased, the tensile and yield strengths will ____________
increase
Dislocations are defects that are responsible for plastic deformation in crystalline solids. If I make it more difficult for dislocations to move will I increase, decrease, or not change the strength of the material?
increase the strength of the material
Chemicals added to molten metals to promote nucleation are known as ________
inoculants
In an extrinsic n-type semiconductor, where is the Fermi level located?
inside the band gap but just below the conduction band
In all crystal structures, there are small holes between the usual atoms into which smaller atoms may be placed. These locations are called __________ sites.
interstitial
Compounds can be formed from two or more metals. When the difference in electronegativity between the metals is very large, these compounds may be bonded by a mixture metallic bonds and ________ bonds
ionic
In _______ materials, a diffusing ion only enters a site having the same charge
ionic
Ceramic materials are generally more brittle than metals. Why?
large resistance to motion, slip is inhibited
A cattive is a collection of points named ___________, which are arranged in a periodic pattern so the surroundings of each point in the lattice are identical
lattice points
A lattice is a collection of points named ____________, which are arranged in a periodic pattern so the surroundings of each point in the lattice are identical.
lattice points
A(n) ________ polymer is a polymer consisting of spaghetti-like molecular chains. A(n) ________ polymer consists of primary polymer chains in addition to secondary offshoots stemming from these main chains.
linear, branched
Oxidation of an atom involves the:
loss of electrons
What are some undesirable characteristics of aluminum?
low melting point
To avoid quench cracks, a metal is first cooled to just above Ms and held until the temperature equalizes in the steel. Quenching after the initial cooling allows all of the steel to transform to martensite at about the same time. This heat treatment is called ______________
marquenching
For composites, the matriculates phase is normally selected to be more or less ductile than the dispersed phase?
more ductile
In many ductile materials, deformation does not remain uniform. At some point, one region deforms more than others and a large local decrease in the cross-sectional area occurs. This phenomenon is know as _________
necking
Referring to the periodic table, polymers are materials that are made up of:
non-metallic element + non-metallic element
________ stress occurs when an applied force acts perpendicular to the area of interest. _______ stress arises when an applied force acts in a direction parallel to the area of interest.
normal, shear
Most of the mass of the atom is contained within the
nucleus
Most of the mass of the atom is contained within the _________
nucleus
When referring to the optical properties of materials, ________ materials are impervious to light transmission; whereas, ________ materials transmit light diffusely and _________ materials transmit light with little absorption.
opaque, translucent, transparant
Planes and their negative values are identical because they are __________
parallel
Which of the following are composites?
pearlite steel, wood, bone, concrete, carbon fiber-reinforced epoxy, ductile cast iron, fiberglass
Keesom interactions are interactions between molecules that are __________ polarized
permanently
________ refers to irreversible deformation that occurs when the force or stress that caused the deformation is removed
plastic deformation
Localized disruptions in otherwise perfect atomic or ionic arrangements in a crystal structure are called __________
point defects
The degree of __________ is defined as (average molecular weight of polymer)/(molecular weight of repeat unit?
polymerization
These materials are typically organic materials, are typically good electrical and thermal insulators, and generally have very good strength-to-weight ratios. They are generally not suitable for high temperature applications.
polymers
Which of the following is not a thermosetting plastic?
polystyrene
All of the following are classifications for electronic materials except ___________
power conductors
Metallic, covalent, and ionic bonds are known as ___________?
primary bonds
The Pauli Exclusion Principle states that within each atom, no two electrons can have the same four ____________ numbers
quantum
What is the refractive index? How do you use Snel's law? What does it tell you? What does it mean to have a high or low refractive index?
ratio of speed of light in a vacuum and speed of light in a medium.
Hot working is done at a temperature that is above which of the following:
recrystallization temperature
In the equation Io = Ir + Ia + It, the Ir, term represents _______, the Ia term represents_________, and the It term represents ________.
reflected, absorbed, transmitted
Photons traveling in a non-vacuum material can easily pass into a second material. The velocities of the incident and ________ beams in these materials depend on the indices of refraction. This relationship is expressed in the equation c1/c2 = n2/n1 = sinθi/sinθt.
refracted
What differentiates atomic structures from crystal structures?
relates to the number of protons and neutrons in the nucleus of an atom, as well as the number and probability distributions of the constituent electrons. Crystal structure pertains to the arrangement of atoms in the crystalline solid material.
During quenching, austenite can be trapped in its own phase instead of turning into martensite. This type of trapped austenite is known as __________ austenite.
retained
What is the mathematical relationship between the atomic radius (r) and the lattice parameter (a0) in the BCC structure?
root(3a0) = 4r
As the porosity of refractory ceramic bricks increases,
strength decreases, chemical resistance decreases, and thermal insulation increases
Increase the number of grains or reducing the grain size of a metallic material causes grain-size ________
strengthening
As the amount of cold work on a metal increases, both the yield strength and the _______ strength will increase
tensile
A critical temperature in the formation of glass is known as the glass- ___________ temperature
transition
The three steps of age hardening are solutions ________, _________, and aging
treatment, quenching
According to Figure 11-6, at a temperature of 100 C and weight of 40% tin exists as ___________ phases
two
Density is a ratio of ___________
weight/volume
