MTL 200 EXAM 4 QUESTIONS AND
100% CORRECT ANSWERS!!
Twinning occurs on (1) crystallographic plane and in a (2) direction.
(1) a definite, (2) specific.
The conditions for a substitutional solid solution are
r (atomic radius) < 15%, proximity in the periodic table (electronegativities), same
crystal structure, and valency
Exhibition of mirror lattice symmetry, where atoms on one side are in mirror-
image positions to those atoms on the other side, it is a
Twin boundary
As the number of grain boundaries in a material increases, what is the effect on
yield strength?
Increases
If the grains in polycrystalline materials have preferred crystallographic orientations, the
material has a
texture
A system is at equilibrium if its free energy is
Maximum
Diffusion is the atomic motion in a predictable fashion and leads
to eliminate concentration differences and to produce a uniform composition.
The energy required to move an atom from a normal atomic position to another normal
site is greater than that of moving an interstitial atom. This may verify that(a)
Substitutional atomic diffusion is less stable than interstitial atomic diffusion.
, Substitutional atomic diffusion is more stable than interstitial atomic diffusion
Interstitial diffusion takes place (1) more rapidly than vacancy diffusion because the
interstitial atoms are smaller and (2) mobile. Also, there are (3) vacant interstitial sites
than vacancies.
(1) more, (2) more, (3) more
Carburizing is a process by which the surface (1) concentration of a ferrous alloy is (2)
by diffusion from the surrounding environment at high temperatures.
(1) carbon, (2) increased
Relative to vacancy diffusion, interstitial diffusion is
more rapid
The negative sign in Fick's first law indicates that diffusion occurs
from a high to a low concentration
This type of diffusion is not subject to local compositional changes
Self-Diffusion
In iron-carbon alloys, self-diffusion of iron occurs by
Vacancy mechanism
A system is at equilibrium if
The system includes the minimum randomness or disorder of the atoms.
Binary phase diagram (Ni-45% Cu) is shown. The tie line at T1 Temperature represents:
Both (a) and (b)
In the solidification process of an isomorphous alloy during equilibrium cooling, the
compositions of liquid and solid phases in the two-phase region will follow
liquidus and solidus lines, respectively.
100% CORRECT ANSWERS!!
Twinning occurs on (1) crystallographic plane and in a (2) direction.
(1) a definite, (2) specific.
The conditions for a substitutional solid solution are
r (atomic radius) < 15%, proximity in the periodic table (electronegativities), same
crystal structure, and valency
Exhibition of mirror lattice symmetry, where atoms on one side are in mirror-
image positions to those atoms on the other side, it is a
Twin boundary
As the number of grain boundaries in a material increases, what is the effect on
yield strength?
Increases
If the grains in polycrystalline materials have preferred crystallographic orientations, the
material has a
texture
A system is at equilibrium if its free energy is
Maximum
Diffusion is the atomic motion in a predictable fashion and leads
to eliminate concentration differences and to produce a uniform composition.
The energy required to move an atom from a normal atomic position to another normal
site is greater than that of moving an interstitial atom. This may verify that(a)
Substitutional atomic diffusion is less stable than interstitial atomic diffusion.
, Substitutional atomic diffusion is more stable than interstitial atomic diffusion
Interstitial diffusion takes place (1) more rapidly than vacancy diffusion because the
interstitial atoms are smaller and (2) mobile. Also, there are (3) vacant interstitial sites
than vacancies.
(1) more, (2) more, (3) more
Carburizing is a process by which the surface (1) concentration of a ferrous alloy is (2)
by diffusion from the surrounding environment at high temperatures.
(1) carbon, (2) increased
Relative to vacancy diffusion, interstitial diffusion is
more rapid
The negative sign in Fick's first law indicates that diffusion occurs
from a high to a low concentration
This type of diffusion is not subject to local compositional changes
Self-Diffusion
In iron-carbon alloys, self-diffusion of iron occurs by
Vacancy mechanism
A system is at equilibrium if
The system includes the minimum randomness or disorder of the atoms.
Binary phase diagram (Ni-45% Cu) is shown. The tie line at T1 Temperature represents:
Both (a) and (b)
In the solidification process of an isomorphous alloy during equilibrium cooling, the
compositions of liquid and solid phases in the two-phase region will follow
liquidus and solidus lines, respectively.
