Conceptual Questions

Ace your homework & exams now with Quizwiz!

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


Related study sets

Word Within the Word Lists #31-35

View Set

Text Structures in Wheels of Change, Part 2

View Set

American History Unit 4 imperialism questions

View Set

Public Speaking: Final Exam (Review)

View Set

Sak- och skadeföräkring (avancerad)

View Set