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90 Cards in this Set

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A cold worked material with a decreased area, maintains that decreased area during annealing"

True

The easiest slippage of atomic planes occurs in the direction of

Highest linear density

Ductile fracture is undesireable because failure is unpredictable and often catastrophic

False

Which an example of a cold work process to strengthen metals?

Forgin 2- drawing2- Rolling 4- extrusion

Material strengthening reduces a materials tendency to undergo dislocation motion thereby increasing ductility

False

Interstitial atoms within a lattice of atoms tend to concentrate at the dislocation position with compressive stress

False

Increasing the number of grain boundaries decreases a materials resistance to dislocation motion

False

Substitutional atoms smaller than the overall lattice atoms tend to concentrate at the dislocation position with compressive stress:

True

The easiest slippage of atomic planes occurs between:

Planes of highest planar density

A material with a fatigue limit will eventually break even if the max stress is below the fatique limit stress

False

Impact testing shows that brittle materials absorb significant energy before fracture

False

Brittle fracture is undesireable because failure is unpredictable and often catastrophic

True

Recrystallization Temp (Tr) is typically < 0.3x melting temp (Tm)

False

With respect to the dislocation line, the extra plane of atoms perpendicular causes compressive stress"

True

Dislocation motion is a form of elastic deformation

False

Fatigue is a decrease in material strength due to cylic loading of the material over time

True

The local stress that causes crack propagation in a material increases with

Increased Crack length

"Solid solutions form lattice strains on adjacent material planes, thereby reducing dislocation motion

True

Substitutional atoms larger than the overall lattice atoms tend to concentrate at the dislocation position with compressive Stress

False

If the critical stress (Tcrss) is less than the resolved stress (Tr), then:"

The Material will elastically deform

Due to fatigue, a material can eventually fail even if the cycle stress is below the yield stress of a material"

True

"Water phases (liquid, gas, solid) can be depicted on a:"

Unary

Which steel transformation product has highest strength?

Martensite

A single liquid phase that transforms into two solid phases is

Eutectic

Which steel transformation product has highest ductility?

Spherodite

At a temp just below 180 'C, the composition of β in C'4 is

97.8

A liquid and solid phase that transforms into one solid phase is:

Peritectic

"This steel has low carbon content, is inexpensive, and used mostly for support structures

Mild Steel

The ionic structure with a coordination number of 6 is

Octahedral

Phase diagrams are a function of:

Temp, pressure, concentration

This steel is easily melted and molded, but too brittle to machine (i.e cold work)

Cast Iron

An impurity in a ceramic causes a charge imbalance

False

Which method is used to pour molten metal into a mold and cool to a final shape?

Casting

Ceramics, due to their highly brittle nature, are tested for strength and modulus by:"

3 point bend test

The Ionic structure with the highest stability and resistance to fracture is

Tetrahedral

A solution is a single phase compostion

True

A single solid phase that transforms into two solid phases is:

Eutectoid

"This steel has highest wear resistance and is used for knives, razors, and tools that hold an edge

Tool steel

Nomenclature for a plain carbon steel with 0.85wt% carbon would be

1085

Which alloy has the lowest density, which is useful in portable electronics and defense weapons?"

Magnesiun

A mixture is a single phase compostion

False

Which is not a forming method for shaping alloys

Casting

Large cooling temperature (ΔT) past a phase boundary creates

Fast Nucleation

Small cooling temperature (ΔT) past a phase boundary creates

Slow nucleation and large crystals

The ionic structure where the anion and cation are of similar size and therefore arrange in a similar manner to most metals is

Cubic

which alloy hash the highest resistance?

Noble

Pure eutectic steel has an overall conce of:

61.9

At a temp just below 180 'C, the weight fraction of eutectic steel in C'4 is calculated by

Q/(Q+P)

At a temp just below 180 'C, the composition of alpha in C'4 is:"

18.3

The following material is completely solid at a temperature below:

180

Isomorphous materials have:

All of the above

"This steel has good wear resistance and is used for wood cutting tools, nuts, and bolts"

Medium carbon steel

"The resolved shear stress (Tr), due to planar slip in a linear direction is maximum at which angle, with respect to the applied shear

45 45

Which is not an example of a cold work process to strengthen metals

annealing

Edge dislocation motion is parallel to the direction of shearing force

true

Which is not a step in addition polymerization

Condensation

Thermoplastics are soft and ductile when used at a temperature (T):

Tg < T < Tm

Which is considered the most difficult material to recycle?

composites

Which additive improves polymer strength

filler (possibly fiber)

Which is not a property of thermoplastics?

doesnt melt, degrades

Which is not a description of a type of copolymer structure

Ordered

Which is not a form of corrosion

Cracking

Thermoplastics are strong and brittle when used at a temperature (T):

T

Anealing a polymer increases crystallinity, which increases ductility and decreases tensile strength"

False

"With respect to the dispersed phase alignment, composites are:"

Stiffest in Longitudinal

The weight-average (Mw) of a polymer tends to be higher than the same polymers number-average (Mn) (Mw>Mn)

True

Which is not a purpose of the dispersed phase of a composite

decreased YS

Thermoplastics can be reformed and recycled at a temperature

greater than melting

Crystalline polymers must have a significantly higher molecular weight than their non-crystalline counterparts

False

Which is a polymer unit that contains an alcohol group?

R- OH

Cathodic metals (larger electomotive force) resist corrosion more than aniodic metals

True

What are the two reactions necessary to cause corrosion

Oxidation

Which is not a property of thermosets?

dont heat and reform

Corrosion is an electrochemical attack that degrades materials

true

Which is a polymer unit that contains an aldehyde group

r-c=0|h

Which is a polymer unit that contains an ether/ester group?

R-O-R

"A repeat unit is a compound, that when reacted, breaks chemical bonds forms the polymer backbone"

False

Name the tacticity: when a specific branch of a polymer repeat unit alternates sides of the polymer backbone

syndiotactic

Name the tacticity: when a specific branch of a polymer repeat randomly alternates sides of the polymer backbone

Atactic

Name the tacticity: when a specific branch of a polymer repeat unit is always on the same side of the polymer backbone

Isotactic

Structural composites are not strong in

Shear

The degree of polymerization (DP) is the Mw of a polymer divided by its monomer's total atomic weight

False

Polymers with large or complex side-groups or branches are less likely to form highly crystalline plastics

True

Which additive reduces polymer degradation

Stabillizer

Which additive reduces polymer strength and improves ductility

Plasticizer

Polyethylene is not typically found in the following product:

Water Bottles

Which is a polymer unit that contains an acid group?

R-c=0|OH

A monomer is the smallest unit of a polymer chain that repeats

False

Which is not a classification of composites:

Polymorphic

The matrix phase of a composite protects and transfers stress to the dispersed phase

True