Met 121 Final

The Met 121 course will focus on which step in the "Manufacturing Sequence"?

The first few weeks of the course hace focused primarily on this aspect of materials.

Materials in this family often exhibit good strength and good ductility. They are also good electrical and thermal conductors.

Materials in this family are typically light weight, but are generally not suitable for elecated temperature applications. They can be used to probide electrical insulation.

In this type of bonding, the bonds are "directional" (wanting a set and limited number of nearest neighbors). The resulting materials have relatively low density.

In this type of bonding, electrons transfer from donor atoms to receiving atoms, creating charged atoms, which then are electrostatically attracted to one another. Electrical conductivity, therefore, requires the movement of atoms and not electrons.

All of the bonding electrons are tied up within molecules in this tupe of bonding. If the charge is not distributed uniformly within the molecules, a weak electrostatic attraction can occur between the polarized molecules.

In a crystalline lattice, the number of adjacent or nearest neighbors is called the:

Metallic-bonded materials prefer crystal structures with ____ packing and a ___ coordination number.

In the body-centered cubic (BCC) crystal structure, atoms touch along the:

The coordination number for a structure that contains close-packed planes is:

The cubic crystal structure that contains close-packed planes stacked in the ABCBC sequence is:

Compared to materials with other structures, materials with the FCC structure tend to:

The packing factor for structures involving stacked close-packed planes is:

The directions of atom-touching in Fcc crystals have the Miller Indices form of:

The Miller indices for direction A are:

The Miller indices for direction B are:

The Miller indices for plane C are:

The Miller indices for plane D are:

Properties that assume different values when measure in different direction are said to be:

Adding imperfections to a commercial metal (already contains defects) will almost always ___ the strength and ___ the ductility.

A material has 16 grains per square inch when biewed at 100x magnigication. According to ASTM, it would have an ASTM grain size number of:

The type of point defect that assumes a significant role in atomic diffusion is the:

The type of crystalline defect whose movement procides the plastic deformation observed in ductile metals is the:

This type of defect is responsible for the strength of metal being considerably less than the calculated theoretical strength of several million pounds per square inch.

Because this structure has four non-parallel slip planes {111} with three slip directions in each for a total of 12 slip systems, it exhibits exceptional ductility.

The total absence of close-packed planes in this structure makes slip extremely difficult (highest critical resolved shear stress), and results in materials with high strength.

According to Schmid's Law (t=o cos y cos a), the applied load is most effective in inducing shear when:

The two most common mechanisms for atom movement (diffusion) are:

In Fick's First Law, J = -D dc/dx, the resultant movement of atoms is represented by this term:

As the temperature is invrease in the range of atomiv diffusion, we would expect the rate of atom movement to ___ with temperature.

We can estimate the temperature where diffusion becomes significat as:

The activation energy (the Q in the D_o= D e ^-Q/RT) is a measure of the:

Since it would be the most tightly-bonded, the highest temperature would be required to activate movement of an atom lying:

Becuase of the type of bond, diffusion would be easiest to activate in materials with ___ bonding.

Which of the following is NOT a standard condition for at ensile test?

In a standard tensile test, the elastic response is associated with:

The stiffness or rigidity of amaterial can be evaluated by this property:

Engineering stress is defined as:

When the elastic-to-plastic transition is not distinct, we often define and agree on:

In the plastic region of the tensile test:

The "ductility" of a material can be measured by which two tensile test properties?

"Toughness" is a measure of a material's:

If we want a steel to not be brittle, it should be used at a temperature ___ its Ductile-to-Brittle Transition (DBTT)

This most coommon form of mechanical failure creates "striations: on the fracture surface.

This tupe of test is the quickest and least expensive to conduct, and is frequently used as a quality control check during manufacturing operation.

An S-N (stress vs. number of cycles) diagram is a collection of data from this tupe of test.

Rockwell and Brinell are the two most common types of ___ test.

Compared to my other courses, I find Met. 121 to be:

Which of the following properties does NOT increase during cold working?

The change in properties that is obserced as we cold work a material is attributed to:

Which of the following is NOT a correct statement wabout cold working?
A. We can strengthen the material while producing a desired shape.
B. Anisotropy and residual stresses are always detrimental and should be removed prior to use
C. Dimensional tolerances and surface finish tend to be good
D. The process is often limited by fracture

Cold working is very effective means of strengthening materials with this crystal structure:

During this stage of annealing, strength continues to drop, but there is no companion improvement in other properties. This stage is usually considered to be undesirable.

During this stage of annealing, new grains nucleate and grow, ductility is restored, and strength drops significantly.

This is the metallurgical "process: that is responsible for the structure and property changes that occcur during annealing.

Which of the following is NOT a possible reason for annealing a cold-worked metal?
A. Relieve residual stresses
B. Enhance conductivity
C. Increase or restore ductility

If we weld cold worked metal, we would expect the metal that is immediately adjacent to the weld to:

During hot working:

Heterogeneous nucleation is most likely to:

If the size of a nucleating solid is less than the critical radius for a griven temperature, ___:

Inoculation is a special means of inducing:

Dendritic growth occurs when the liquid lying just ahead of the solidification interface is:

If a cooling curve contains a "thermal arrest", the material is:

Because of its unique grain structure, properties in this cast region are always anisotropic (vary with direction):

Deoxidation and vacuum processing are two means of reducing or eliminating:

Solid solution strengthening can be obtained through the addition of:

The atomiv radii of copper, zinc, aluminum, and tin are listed below. Based on this information, we would expect that the greatest increase in strength would be achieved through the addition of 2 percent of ___ to pure copper. ATOMIC RADII: Cu=1.278A; Zn=1.332A; Al=1.432A

When we use solid solution strengthening to alter the properties of a metal, which of the following properties would be expected to DECREASE?

Aluminum has a face-centered-cubic crystal structure. Magnesium is hexagonal-close-packed. As a result we would expect the solubility of magnesium in aluminum to be:

If an alloy has a freezing range, complete solidification occurs when the temperature reaches the:

The "tool" used to determine the composition (or chemistry) of the phases present in a two-phase mixture is the:

For the 50% Bg alloy, the solidus temperature is approximately:

Upon cooling the 50% Bg alloy, the first solid to appear will be expected to have the composition of:

If the 50% Bg alloy were cooled to 500 C under equilibrium conditions, we would expect to find ___% solid material.

The chemistry of the solid present when the 50% Bt alloy is in eqyilibrium at 500 C is:

The eutectic composition is ___ and the temperature of the eutectic reaction is ___.

The maximum solubility of Sn in Cg is:

The amount of primary beta phase that would appear in the 80% Sn alloy upon equilibrium cooling could be computed by which relation?

For the 80% Sn alloy, the amount of eutectic structure present at room temperature can be best extimated by:

The 80% Sn alloy would be considered to be:

The composition of the last liquid to freeze during the equilibrium cooling of the 80% Sn alloy would be:

The room temperature structure of the 80% Sn alloy would be best described as:

Which alloy listed below would be the best candidate for age hardening?

The sloped line separating the alpha and the alpha+beta region of the diagram is a ___ line.

400 C
Eutectic
Eutectoid
Peritectic
Peritectoid
Monotectic

600 C
Eutectic
Eutectoid
Peritectic
Peritectoid
Monotectic

Alpha phase would be a:

Beta phase would be considered to be a:

The generic form of a peritectoid reaction is:

In the solution treat - quench - and age treatment sequence, the material is a supersaturated single phase solid solution:

To age a solution treated and quenched material, we should heat it:

Which of the following statements is not true for age hardening?
The reulting structure is non-equilibrium and will change if sufficiently heated
A second-phase particle is a more effective strengthener than a coherent precipitate
Age hardened materials will lose strength when they are fusion welded
The precipitated phase can be brittle, since it is discontinuous

If elevated temperature is required to promote aging, the material is considered to be:

If we increase the temperature of aging, we would expect the peak strength to ___, and the time required to achieve that strength to ___.

The solution treatment step in age hardening is performed by heating the material to a temperature that is:

Which of the following strengthening mechanisms would be preferred if we wish to retain useful strength at elevated temperature?

In a lamellar eutectic structure, much of the observed strength can be attributed to:

That to Met. 121, I now know:

In the iron-carbon equilibrium phase diagram, the eutectoid transformation of ausstenite to pearlite occurs upon crossing the ___ line.

The single phase known as ___ is really an intermetalic compound that forms between carbon and iron.

The room temperature BCC single phase that has a maximum solubility of only 0.02% carbon is known as:

The elevated-temperature single-phase solid solution that can hold up to 2.11% dissolved carbon is known as:

Most heat treatments begin with the formation of this structure, since it erases prior structures and its high solubility allows carbon and alloy elements to redissolve:

This microstructure is a lamellar or layered mixture of alpha and FE₃C.

According to the equilibrium phase diagram cementite should always have a composition of:

The primary phase that forms when cooling a hypoeutectoid steel between the A₃ and A₁ temperatures is:

Which of the following is not an equilibrium single phase? i.e. one that appears in the iron-carbon equilibrium diagram?
Ferrite
Cementite
Austenite
Martensite

The amount of pearlite in an equilibrium-cooled 0.6 carbon steel would be about:

The composition of the pearlite that forms in an equilibrium-cooled 0.6 carbon steel would be:

The microstructure that forms below the nose but above the M_s temperature on a TTT (or IT) diagram is knkown as:

Because the formation of martensite is a diffeusionless transformatin, the resulting martensite will always have a carbon content equal to:

Arrange the following microstructures of the TTT diagram in order of increasing strength:

Because martensite is a supersaturated solid solution of carbon in ron, the strength of martensite depends almost exclusively on:

When martensite is heated to a temperature below the A₁, the process is called:

During tempering, martensite ___ strength and ___ ductility.

In the terms "coarse peralite" and "fine pearlite", the terms coarse and fine refer to:

If austenite has partially transformed to martensite and we wish to form more martensite, we should:

An 8620 steel is a ___ steel with ___% carbon.

The heat treatment whose primary purpose is to enchance the machinability of high carbon steels by altering the form of the cementite is known as:

Compared to normalizing of the same material, a full anneal will generally take ___ time and result in a final structure with ___ ductility.

Which of the following heat treatments is a final heat treatment designed to harden and strengthen the material?
Full anneal
Normalize
Spheroidize
Quench & Temper

The slowest rate of cooling owuld be observed during:

An austempering treatment will result in the formation of a ___ microstructure:

Retained austenite is most likely to form in a ___ steel?

The primary cause of quench cracking in steel is the fact that when the FCC austenite transforms to a low-temperature body-centered product, the material ___.

Which of the following quench media would likely produce the fastest cooling?

If a steel is cooled faster than the "critical cooling rate", we would expect the final microstructure to be:

Compared to plain carbon steels, alloy steels have ___ hardenability, i.e. their critical cooling rates are ___.

4340 and 8640 steels have the same carbon content. According to the Jominy curves provided:

A 9310 steel is austenitized and quenched to produce an as-quenched hardness of R_c40. If the process is not altered, but the steel is replaced by a 4320, we would expect the as-quenched hardness to be R_c___.

Using the Jominy curves, we find that a good indicator of the carbon contect of a steel would be:

The highest strength steels would come from this category?

The surface-modification treatments such as flame hardening, induction hardening and carburizing are usually employed to produce:

Flame hardened or induction hardened surfaces resist quench cracking and have good fatigue life because the resulting surfaces have __ residual stresses.

Stainless steels have good corrosion resistance because of the:

In order to be considered as a true stainless steel, an iron-based metal must contain more than:

This type of stainless can contain sighificant amounts of carbon and achiebes musch of its strength from phase transformation hardening.

This family of stainless steel is the cheapest, and it achieves most of its strength from solid solution strengthening.

This type of stainless can be easily identified and separated from the other tupes since it is not strongly attracted to a magnet.

The family of stainless steels that offers the greatest ductility and formability (because of its FCC crystal structure) is:

Cast irons are alloys of:

The best ductility and fracture resistance are observed in this type of iron where smooth-surface graphite sheres form directly upon solidification.

This type of cast iron is used almost exclusively for wear-resistance applications. It is extremely hard and brittle because the excess carbon is all in the form of Fe₃C.

Compacted graphite cast iron has a structure and properties that are intermediate between ___ and ___.

Graphite "flakes" are the characteristic feature that idenities ___ cast iron.

The type of cast iron that uses a long-time, elevated-temperature heat treatment to produce graphite clumps is:

A cast iron alloy contains 2.8% carbon, 1.8% silicon, 1% chromium, and 1% nickel. Its carbon equivalent is:

Having completed this third hour exam, I can honestly say:

Which of the following is not an attractive asset of aluminum and aluminum alloys?
Easy to fabricate
Very ductile
Good wear, creep, and fatigue properties
Good electrical and thermal conductivity

The corrosion resistance of aluminum is attributed to:

For aluminum alloys, the highest strength is achieved through:

The best corrosion resistance would be found in ___ aluminum alloys

In the aluminum alloy designation 7075-T6, the T6 suffix denotes the:

Magnesium alloys are designated by a:

Compared to aluminum, magnesium alloys are:

This is the ony lightweight metal that is also considered to be an "elevated temperature" material, retaining useful strength up through 500C or 900F.

Which of the following lightweight metals would be capable of possessing the highest strength?

This lightweight metal is unique in being lighter than aluminum, but stiffer tahn steel. Unfortunately it is also brittle and sometimes considered to be toxic.

Users of this metal are often willing to accept its negative properties and characteristics in order to gain the weight savings offered by this lightest of the engineering metals.

Copper and copper alloys are msot often used for their:

When we need useful strength and corrosion resistance at elevated temperature, we might want to consider:

The nickel-base alloy that has been described as having "better corrosion resistance to more media than any other commercial alloy" is:

The superalloy metals are usually based on which two metals?

The upper limit to the practical application of the refractory metals is closest to:

The upper limit to the application of the supperalloy metals is closest to:

Which of the following ould be considered to be a refractory metal?

Which of the following is not a characteristic property of ceramic materials?

The bonding in ceramic materials is:

Since glass is a(n) ___ structure, ist formation requires a cooling rate ___ than some critical value.

The crystalline ceramics anre brittle because:

A metal matrix provides toughness and fracture resistance in:

Tempered glass acquires its fracture resistance through:

The uuses and applications of ceramic materials are usually dominated by their:

The excellent high temperature properties of ceramic materials make them excellent candidate materials for use as:

Nominally "identical" ceramic products often fail at widely different mechanical loads becasue:

Which of the following properties is not an asset of polymeric materials?

In our "cotten ball" model of linear polymers, the bonding within the fibers would be ___, with the bonding between the molecular fibers being ___.

The recyclable polymers are almost always:

Three-dimensional network polymers form when the reacting mers have a functionality of:

Which of the following is not likely to increase the strength of a linear thermoplastic polymer?

When fabbricating products from thermoplastics polymers, production may be slowe becasue we must:

The linear moecules in this tupe of polymer act like coilded springs, uncoiling and recoiling with the application and removal of the mechanical loads. A good example is a rubber band.

In general, the stiffest (most rigid) polymers have an elastic modulus that is:

Which of the follwoing is not an attractive feature of adhesive bonding?
Adhesives are light in weight
The joints offer good strength at elevated temperatures (in excess of 500F)
All the materials and combinations can be joined
Joints can be formed at low temperatures (often room temp)

Which of the following is not a correct statement regarding composite materials?
Composite materials can be easily separated and recycled
Distinct interfaces are present betweeen the component materials
The components can be metals, ceramics, polymers, or even natural materials
Each component retains its identity, structure and properties

Because of their geometries, the properties of ___ composites are ALWAYS ANISOTROPIC, while the properties of ___ composites are ALWAYS ISOTROPIC.

In fiber-reinforced composites, the term "specific strength" refers to the ratio of:

The aspect ratio of a reinforcing fiber is the ratio of its:

In a fiber-reinforced composite, we ask the matrix material to do all of the following except:
Probide ductility and toughness
Probide strength and stiffness
Supposrt the fibers
Probide desired electrical or thermal conductivity

Which of the following is not a significant limitation to the use of fiber-reinforced composites?
They have poor stiffness and fatigue life
Difficult to repair
Difficult to inspect
Joining is severely limited

The Rule of Mixtures predicts properties based on:

The highest operating temperatures in te fiber-reinforced composites can be achieved with a ___ matrix

According to the government studies on corrosion, about ___% of allcorrosion could have been avoided at no additional cost - the ignorance or stupidity factor.

In a galvanic corrosion cell, corrosion occurs at the __ where electrons are ___.

The current U.S. penney is copper plated zinc. If the copper plating is somehow ruptured or scatched through, the subsequent corrosion will occur in the:

In an oxygen concentration corrosion cell, the accelerated corrosion occurs in the material adjacent to the:

The corrosion resistance that is imparted by zinc coating steel (galvanizing) is achieved by the mechanism of:

Based on what I've learned in Met. 121--