BMEN 343 Exam 2 Small Group Discussion (#11-#18) Questions & Random Definitions

Classification of unit cell geometry and atom position:

a) Crystal system

b) Crystal structure

b) Crystal structure

A type of point defect:

a) Vacancy

b) Self-interstitial

c) Both

c) Both

Provide a concise definition of an alloy

2 or more metallic elements and maybe some small amount of non-metal

A solid solution of complete solubility is characterized by a lack of new structures or phases.

a) True

b) False

a) True

A type of solid solution that wherein impurities occupy regular host atom spots.

a) Substitutional solid solution

b) Interstitial solid solution

a) Substitutional solid solution

A Hume-Rothery Rule for a substitutional solid of complete solubility is:

a) Differences in atomic mass within 15%

b) Differences in atomic radii within 15%

b) Differences in atomic radii within 15%

An FCC metal and BCC metal can form a substitutional solid solution of complete solubility as long as metals have similar electronegativity.

a) True

b) False

b) False

For an edge dislocation, the magnitude of the Burger's vector increases with proximity to the dislocation.

a) True

b) False

a) True

For an edge dislocation, the Burger's vector is (fill in blank) to the dislocation line.

a) Perpendicular

b) Parallel

a) Perpendicular

For a screw dislocation, the Burger's vector is (fill in blank) to the dislocation line.

a) Perpendicular

b) Parallel

b) Parallel

Permanent deformation of a metal increases dislocation density.

a) True

b) False

a) True

Grain boundaries promote movement of dislocations (i.e., make movement easier).

a) True

b) False

b) False

In an ionic solid, a defect consisting of a cation-vacancy and anion-vacancy pair.

a) Schottky Defect

b) Frenkel Defect

a) Schottky Defect

During elastic deformation:

a) Bonds only stretch

b) Bonds only break

c) Bonds both stretch and break

a) Bonds only stretch

Elastic deformation is irreversible.

a) True

b) False

b) False

During elastic deformation of a metal, Hooke's law is obeyed.

a) True

b) False

a) True

Elastic deformation occurs at relatively low strains.

a) True

b) False

a) True

Increased bond strength produces an increase in the elastic modulus.

a) True

b) False

a) True

The elastic modulus of SS316L is greater than that of cortical bone.

a) True

b) False

a) True

During plastic deformation, Hooke's Law is observed

a) True

b) False

b) False

Upon formation of a "neck" during a tensile test of a metal specimen, all subsequent deformation occurs beyond the area of the neck.

a) True

b) False

b) False

Dislocation motion gives rise to:

a) Elastic deformation

b) Plastic deformation

b) Plastic deformation

Dislocation motion involves:

a) Bond stretching

b) Bond breaking

b) Bond breaking

If dislocation motion is inhibited (i.e., reduced), both yield strength and tensile strength will increase.

a) True

b) False

a) True

Low angle grain boundaries disrupt slip more than high angle grain boundaries.

a) True

b) False

b) False

"Alloying" is another term for "solid solution strengthening"

a) True

b) False

a) True

For an alloy, impurity atoms tend to segregate around dislocations so as to minimize lattice strain.

a) True

b) False

a) True

Impurity atoms that are smaller than host atoms tend to localize adjacent to the dislocation line and below the slip plane.

a) True

b) False

b) False

If dislocation motion ("slip") is inhibited, tensile strength and yield strength will increase.

a) True

b) False

a) True

During annealing, ductility increases while tensile strength remains constant.

a) True

b) False

b) False

The stage annealing associated with the greatest change in mechanical properties.

a) Recovery

b) Recrystallization

c) Grain Growth

b) Recrystallization

During annealing, the number of dislocations within grains decreases.

a) True

b) False

a) True

Annealing of a previously cold worked alloy leads to:

a) Increased tensile strength and increased ductility

b) Increased tensile strength and decreased ductility

c) Decreased tensile strength and increased ductility

c) Decreased tensile strength and increased ductility

Hot-rolling a previously cold worked block of SS 316L would increase ductility.

a) True

b) False

a) True

The modulus of a particular alloy is expected to increase after annealing.

a) True

b) False

b) False

The ductility of a particular alloy is expected to increase after annealing.

a) True

b) False

a) True

Toughness is a measure of a material's ability to:

a) absorb energy and plastically deform before fracture

b) absorb energy without permanent deformation

c) resist local plastic deformation

a) absorb energy and plastically deform before fracture

For a metal specimen undergoing a tensile test, the neck begins to form at the yield point.

a) True

b) False

b) False

What accurately describes a ceramic?

a) Comprised of 2 or more metallic elements and optionally, minor amounts of non-metallic elements

b) Comprised of 2 more elements where at least 1 element is a non-metal.

b) Comprised of 2 more elements where at least 1 element is a non-metal.

Ceramics exhibit what type of primary bonds?

a) Metallic

b) Covalent

c) Ionic

c) Ionic

In a 3-point bend test of a ceramic rod, tension is produced on the:

a) Top face

b) Bottom face

b) Bottom face

The modulus of Cr-Co alloys are higher than that of titanium alloys.

a) True

b) False

a) True

The main components of ASTM F90/Haynes-Stellite F90 are:

a) Co-Cr-Mo

b) Co-Cr-W-Ni

c) Co-Ni-Cr-Mo-Ti

b) Co-Cr-W-Ni

A cast alloy may be subjected to forging.

a) True

b) False

b) False

Alumina is expected to induce bone tissue formation when implanted in the body (i.e., is bioactive).

a) True

b) False

b) False

Pyrolitic carbon and graphite are both allotropes of carbon.

a) True

b) False

a) True

PyC-SiC has superior thromoresistance versus PyC.

a) True

b) False

b) False

Yielding

onset of plastic deformation

Toughness (or Facture Toughness)

measure of a materials ability to absorb energy and plastically deform before fracture

Resilience

ability to absorb energy without permanent deformation

Hardness

resistance to local, plastic deformation