Metallurgy Test 4

Which of the following is NOT a limitation of polymeric materials? A. Poor corrosion resistance C. Low strength B. Low rigidity D. Poor dimensional stability

A

A co-polymer is: A. A polymer with two or more different types of mers in the same chain B. A mix of thermoplastic and thermoset resins C. An elastomer that has been cross-linked D. A polymer that has become partially crystallized

A

Alloys of this metal and lithium have been well received in the aerospace industry due to their high strength, high stiffness and light weight. A. Aluminum B. Magnesium C. Beryllium D. Cobalt

A

Brick, tile, dinnerware, and even ceramic sinks and toilets are examples of: A. Clay and whiteware products C. Refractories B. Cermets D. Abrasives

A

Color anodizing, a process in which a colored dye is trapped in the surface oxide, is a common surface finishing process used with ___ alloys. A. Aluminum B. Magnesium C. Titanium D. Copper

A

Compared to thermoplastic polymers, the thermosets tend to be: A. Stronger and stiffer C. Far more elastic B. Lighter in weight D. More easily recycled

A

Composite materials are often rated by "specific strength" and "specific stiffness". In these terms, strength and stiffness is combined with what other property? A. Density or weight C. Melting point B. Ductility D. Toughness

A

Dispersion-strengthened particulate composite utilize small amounts of small ceramic particles to impart: A. Strength at elevated temperatures C. Enhanced toughness B. Improved conductivity D. Higher stiffness

A

Ethylene has a chemical formula of C2H4. Vinyl chloride is C2H3Cl. Because the side chlorine atom is larger than hydrogen, we would expect polyvinyl chloride (PVC) to be ___ polyethylene. A. Stronger than B. Weaker than C. The same strength as

A

High ductility, fracture resistance and good strain hardening characteristics are all attractive features of a: A. Wrought alloy B. Cast alloy C. Amorphous metal

A

If an aluminum alloy bears the standard designation of 6061-T6, we can conclude that it is a: A. Heat-treated wrought alloy C. Casting alloy B. Cold-worked wrought alloy

A

If we cold work (plastically deform) a linear thermoplastic polymer, such as polyethylene, the chains move from a random orientation to a more parallel form of alignment. As a result, the strength will: A. Increase B. Remain unchanged C. Decrease

A

If we cold work (plastically deform) a linear thermoplastic polymer, the chains move from a random orientation to a more parallel form of alignment, and the strength: A. Increases B. Remains unchanged C. Decreases

A

In a fiber-reinforced composite, we usually expect ductility and toughness to be imparted by the: A. Matrix B. Reinforcing fiber

A

Magnesium alloys are: A. Lighter than aluminum C. Good in wear, creep and fatigue applications B. Exceptionally ductile D. Easily strengthened by a variety of techniques

A

The Rule of Mixtures: A. Can accurately predict the density of a composite material B. Can accurately predict most mechanical and physical properties of a composite C. Includes consideration of size, shape, distribution and orientation of the components D. All of the above

A

The Rule of Mixtures: A. Predicts properties as a weighted average of the properties of the components B. Can accurately predict most mechanical and physical properties of a composite C. Includes consideration of size, shape, distribution and orientation of the components D. All of the above

A

The adhesive in a hot-melt glue gun would be some form of: A. Thermoplastic polymer C. Low melting point metal B. Thermosetting polymer D. Ceramic

A

The class of polymer that is most easily recycled is: A. Thermoplastic B. Thermoset C. Elastomer

A

The class of polymer that is most easily recycled is: A. Thermoplastic B. Thermoset C. Elastomer.

A

The good corrosion resistance of titanium and titanium alloys can be attributed to: A. An adherent, protective oxide film B. Low chemical reactivity of the metal itself

A

The lightweight metal that has outstanding formability, and is known for its ease of fabrication by a wide variety of processes: A. Aluminum B. Magnesium C. Titanium D. Beryllium E. Tungsten

A

The type of composite in which the properties are ALWAYS anisotropic is: A. Laminar B. Particulate C. Fiber-reinforced

A

The type of composite that ALWAYS has anisotropic properties is the ___ variety. A. Laminar B. Particulate C. Fiber-reinforced

A

This class of ceramic material accounts for over half of the ceramic material market (by volume), and has found a wide range of commercial applications. A. Glass and glass products C. Electrical and magnetic ceramics B. Refractories D. Clay products

A

Under mechanical loading, the strength of a ceramic when loaded in compression would most likely be: A. Much higher than its strength in tension B. Much lower than the strength in tension C. The same as its tensile strength

A

A major limitation to structural adhesives is: A. The adhesive promotes galvanic corrosion B. Adhesives cannot be used at elevated temperatures (above 350 F) C. Structural adhesives are expensive compared to welds or fasteners D. Only metals can be joined

B

A material with a standard designation of AZ61 is an example of an alloy of: A. Aluminum B. Magnesium C. Titanium D. Copper

B

Aluminum alloys can be strengthened by a number of techniques. The greatest increase in strength is achieved through: A. Grain size control C. Cold working B. Age hardening D. Solid solution strengthening

B

Aluminum is face-centered cubic. Magnesium is hexagonal-close-packed. Alloyed titanium or titanium at elevated temperature is body-centered cubic. The metal that we would expect to be "brittle" would be: A. Aluminum B. Magnesium C. Titanium

B

At room temperature, fine grain size (small crystals) provides the best properties for a ceramic material. When ceramics are to be used at high elevated temperatures, we generally want: A. Fine grain size as well B. Large grain size

B

Compared to aluminum, magnesium alloys are generally: A. Stronger B. Lighter in weight C. More corrosion resistant D. More ductile

B

Compressive residual stressed induced by rapid cooling are responsible for the improved toughness in: A. Cermets C. Transformation toughened ceramics B. Tempered glass D. Stabilized zirconia

B

High hardness ceramics are often used in tools for cutting operations, as grit in "sandpaper", and as the particles in grinding wheels. Materials used for these applications are called: A. Refractories C. Whiteware B. Abrasives D. Cermets

B

Identical ceramic parts often fail over a wide range of tensile strengths. This can be attributed to variations that occur in the: A. Chemistry (i.e. purity) C. Grain size B. Flaw size and location D. Heat-treatment (i.e. firing)

B

If we cool a ceramic material at a rate that is faster than the "critical cooling rate", we are likely to produce a material with a: A. Crystalline structure B. Glass structure

B

If we progressively increase the degree of cross-linking in a polymer, we would expect the material to become ___ and ___ ductile. A. Stronger , more C. Weaker, more B. Stronger, less D. Weaker, less

B

In a fiber-reinforced composite, strength and rigidity is normally provided by the: A. Matrix B. Reinforcing fiber

B

Monel, the corrosion-resistant alloy that is often used in applications where stainless steel proves to be inadequate, is actually an alloy of this metal and copper. A. Cobalt B. Nickel C. Beryllium D. Titanium

B

Since the Y.S. strongest / Y.S. weakest ratio for this metal is exceptionally small (about 3), designers must design to the material rather than having the material be tailored to the design. A. Aluminum B. Magnesium C. Copper D. Titanium

B

The "degree of polymerization" is a term that refers to the: A. Number of locations on a mer where linking can occur B. Average number of mers in a polymerized chain C. Range of temperatures over which a polymer can be used D. The temperature required to induce a thermoset polymerization reaction

B

The bonding WITHIN the individual chains of a linear thermoplastic polymer is: A. Ionic B. Covalent C. Metallic D. VanderWaals

B

The ceramic structure that is non-equilibrium in nature and requires rapid cooling to produce is: A. Crystalline B. Non-crystalline or glass

B

The exceptionally high elasticity that is observed in the elastomers is attributed to: A. The exceptional stretching ability of vanderWaals bonds B. The uncoiling of twisted or curled linear molecules C. The easy movement of dislocations in polymers D. The three-dimensional covalent bonding

B

The fracture resistance (or toughness) of glass can be increased by "tempering". In this process: A. We quench to form martensite and then reheat to precipitate carbon B. Rapid cool the glass to induce compressive residual stresses on the surface C. Incorporate metastable phases that expand and stop cracks D. Make sure that the crystals within the glass have a fine grain size

B

The heat-treatable, high-strength, aluminum alloys are strengthened by age hardening. Because the precipitate will have a different chemistry than the continuous matrix, these alloys (compared to the single-phase non-heat-treatable alloys) tend to have: A. Better corrosion resistance B. Poorer corrosion resistance

B

The oxide of this metal has been shown to be potentially toxic. As a result, extreme caution is required in its use. A. Aluminum B. Beryllium C. Magnesium D. Titanium

B

The upper limit to the application of the superalloy metals is in the neighborhood of: A. 500 F (250 C) C. 3000 F (1700 C) B. 2000 F (1100 C) D. Shouldn't be used at elevated temps.

B

This is the ONLY elevated temperature metal to also be considered as a lightweight metal. A. Aluminum B. Titanium C. Nickel D. Cobalt E. Tungsten

B

This polymer structure is expected to offer the highest strength and rigidity, but may be brittle. A. Linear (or chain-type) B. Network

B

When fabricating parts of this type of polymer, individual resins are mixed and injected into heated molds, where they react or cure to form the polymer. Mold temperature remains constant from part to part. A. Thermoplastic B. Thermoset C. Elastomer

B

Which of the following is NOT a common characteristic of fiber-reinforced composites? A. High cost C. Assembly usually requires adhesives B. Easily recycled D. High strength and stiffness

B

Alloys of this metal are used to replace steel when high strength must be retained but weight reduced. It is also used in place of aluminum when we want light weight, but elevated temperature service is anticipated. A. Beryllium B. Magnesium C. Titanium D. Copper

C

An identifying characteristic of condensation polymerization is: A. An elastomeric product C. Production of a by-product molecule B. It cross-links D. It produces crystalline polymers

C

Cobalt is considered to be a: A. Lightweight metal C. Superalloy B. Refractory metal D. Ceramic

C

If ceramic materials are to achieve the goal of good mechanical properties under a variety of loads (including tensile), we will have to successfully: A. Develop new ceramics with new compositions B. Produce faster means of cooling (quenching) C. Improve processing to reliably reduce flaw size

C

In order to produce a network or framework polymer, we must have reacting mers with a functionality of: A. One B. Two C. Three or more D. Any positive value

C

Molybdenum and tungsten are two of the: A. Lightweight metals B. Superalloys C. Refractory metals D. Ceramic coatings

C

Monel - an alloy described as having "better corrosion resistance to more media than any other commercial alloy" is best described as a(n) ___ alloy. A. Aluminum B. Titanium C. Nickel D. Tungsten

C

Temperatures of 1000 C or 2000 F would be near the upper limit of the useful range of: A. Aluminum B. Titanium C. Superalloys D. Refractory metals

C

The aspect ratio of a reinforcing fiber is the ratio of its ____. A. Tensile strength to density C. Length to diameter B. Stiffness to density D. Tensile strength to stiffness

C

The fabrication of automobile body panels from thermoplastic sheets takes longer than the pressforming of metal because: A. We must provide sufficient time for the resins to react or "cure" B. We need to form sufficient cross-linking to provide strength C. We need to cool the part before it can be removed from the mold

C

The lightweight metal that offers the strength of heat-treated steel at nearly half the weight (plus the ability to use it at moderately elevated temperatures): A. Aluminum B. Magnesium C. Titanium D. Beryllium E. Tungsten

C

The structures of ceramic materials are typically far more complex compared to those for metals. Which of the following is NOT a contributor to this complexity? A. Atoms of differing size must be accommodated B. Charge neutrality must be maintained C. The individual ceramic molecules can be extremely long D. The number of neighbors may be limited by the type of bonding

C

The superalloys are generally based on which two metals? A. Aluminum and magnesium B. Beryllium and titanium C. Cobalt and nickel D. Tungsten and tantalum

C

This lightweight engineering metal has outstanding machinability, but one must exercise caution since the chips can ignite and burn. A. Aluminum B. Beryllium C. Magnesium D. Titanium

C

When producing a laminar material, such as corrugated cardboard or honeycomb, our objective is often to impart: A. Improved fracture resistance C. Enhanced strength and stiffness B. Shape as a function of temperature D. Improved corrosion resistance

C

When this type of matrix is used in a composite material, we often want weak bonding between the components, rather that the usual strong. A. Polymer matrix B. Metal matrix C. Ceramic matrix

C

Which of the following is NOT a characteristic property of ceramic materials? A. High compressive strength B. Hard but brittle C. Good electrical and thermal conductivity D. High melting temperature

C

Which of the following is NOT an asset or positive attribute of aluminum? A. Good ductility B. Good electrical conductivity C. Good wear, creep and fatigue properties D. Good corrosion resistance

C

Which of the following properties is NOT an asset of polymeric materials? A. Ease of fabrication C. Retains strength at elevated temperatures B. Light weight D. Can have integral color

C

Wrought alloys are materials that are: A. Age hardened C. Shaped as a solid B. Cast to final shape D. Unable to be heat-treated

C

Which of the following is NOT a true statement about polymers? A. Crystallized polymers are stronger than amorphous ones B. Framework polymers are more rigid than linear C. All polymers do not have high ductility (percent elongation) D. The strongest polymers are as strong and as rigid as engineering metals

C or D

Ceramic coatings are generally required for the high temperature environments encountered by: A. Aluminum B. Titanium C. Superalloys D. Refractory metals

D

Ceramic materials often have complex crystal structures because: A. Charge neutrality must be maintained in ionic materials B. Covalent materials have restricted numbers of neighbors C. Atoms of greatly differing size are often involved D. All of the above

D

If we wish to increase the strength of a chain-type polymer, we can ___ the amount of activator or catalyst to ___ the average length of the chain molecules. A. Increase, increase C. Decrease, decrease B. Increase, decrease D. Decrease, increase

D

In order to function at extreme elevated temperatures, ceramic coatings must be applied to this material to isolate it from gases that would react and cause failure. A. Copper B. Titanium C. Superalloy metal D. Refractory metal

D

The bonding that occurs BETWEEN the individual chains of a linear thermoplastic polymer, such as polyethylene, is: A. Ionic B. Covalent C. Metallic D. VanderWaals

D

The high hardness of ceramic materials is utilized in this type of application: A. Clay and whiteware products C. Refractories B. Cermets D. Abrasives

D

The use of this lightweight metal is often limited by its "toxicity" and the associated precautions and costs. A. Aluminum B. Magnesium C. Titanium D. Beryllium E. Tungsten

D

This metal has the best electrical and thermal conductivity of the nonferrous metals, and has become the industry standard for these properties. A. Aluminum B. Magnesium C. Titanium D. Copper

D

Un-reinforced concrete is a classic example of which type of composite material? A. Laminar C. Dispersion-strengthened particulate B. Fiber-reinforced D. True particulate

D

Which of the following is NOT a characteristic property of ceramic materials? A. High melting temperature B. Hard but brittle C. Poor electrical and thermal conductivity D. Poor corrosion resistance and chemical stability

D

Which of the following is NOT an asset of aluminum and aluminum alloys? A. Light weight C. Good corrosion resistance B. High ductility D. Good in wear, creep and fatigue applications

D

Which of the following is NOT an asset of copper and copper alloys? A. Good formability C. Good electrical and thermal conductors B. Good corrosion resistance D. Excellent retention of strength at elevated temps.

D

Which of the following is NOT an attractive feature of adhesive bonding? A. All materials and combinations can be joined B. Elevated temperatures are not required C. Adhesives are light in weight D. Joints can be easily disassembled and reassembled

D

Which of the following properties is NOT characteristic of polymeric materials? A. Poor at high temperature C. Poor electrical & thermal conductivity B. Light weight D. High strength and stiffness

D