©BRIGHTSTARS EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
MSE 250 Final Exam Study Guide.
Liquidus line - Answers✔defines complete liquid )(above the line). First solid forms right below
it.
solvus line - Answers✔separates full solid from some liquid (solid below line)
eutectic reaction - Answers✔point where liquid and 2 solids are in equilibrium. Lowest melting
point
phase - Answers✔a region of a material that is chemically and physically uniform
The following can be determined from a phase diagram - Answers✔Phases present, composition,
melting temp, and amount of phases present.
TiNi3 Phase type - Answers✔intermetallic phase because it was 3Ni so it shows some nickel
stoichometry- suggests electron transfer
NiTi Phase type - Answers✔only says Ni & Ti coexist in the phase, doesn't say anything
chemically so it is intermediate phase. There's nothing to charge balance it so it can form many
crystal structures to be happier.
Eutectic transition - Answers✔liquid to solid (of 2 phases). L--> a + b
Congruent transition - Answers✔liquid to solid. L-->S of one phase
BCC Miller Indices - Answers✔Direction- [111], Planes- (110), no close packed planes
FCC Miller Indices - Answers✔Directions - [101],[110]. Planes - (1,-1,1)
HCP Miller Indices - Answers✔Directions - [100]. Planes - (001) or (000)
BCC Elements - Answers✔Iron, chromium, sodium, potassium
FCC Elements - Answers✔aluminum, copper, gold, nickel, and lead
HCP Elements - Answers✔cadmium, cobalt, titanium, zinc
Schotsky Ceramic Defect - Answers✔Cation and anion vacancy
1
, ©BRIGHTSTARS EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Frankel Ceramic Defect - Answers✔Cation moves and creates a vacancy, then it becomes an
interstitial to another cation
Creep - Answers✔deformation of static stresses examined at high temperatures
First stage of creep - Answers✔Primary - lots of dislocations as pull starts. Much strain in
response
Second stage of creep - Answers✔Secondary - steady strain rate as they get used to it
Third stage of creep - Answers✔Strain rate increases dramatically, too many dislocations (passed
equilibrium). Necting, rupture--> crack formation
3 creep mechanisms/causes - Answers✔diffusion of vacancies, dislocations, and grain
boundaries
Diffusion creep mechanism - Answers✔diffusion of vacancies - they move around. Bigger
grains, hard to move, so decreases diffusion. Longer diffusion paths
Dislocation creep mechanism - Answers✔creates strain hardening and dislocations.
Deformations are carried by dislocation motion. Climb via diffusion.
Grain boundary creep mechanism - Answers✔Prone to creep and cracks. They can grow into
obsesses as the boundaries slide
Screw verses edge dislocation - Answers✔Screw - parallel to bergers vector. Edge- perpendicular
to mergers vector.
Solid solution XX - Answers✔Alloying--add small atoms that pin dislocations. Small impurities
above slip planes, large below in region of tensile strains (think mass of item in water)
slip plane direction - Answers✔only happens in close packed planes
Fatigue limit - Answers✔
Rocksalt - Answers✔NaCl - CN = 6. Cations prefer octahedral sites.
CsCl - Answers✔Ceisum chloride. CN = 8. Cubic sites preferred
ZnS - Answers✔Zinc sulfide. CN = 4, cations occupy tetrahedral sites.
CaFa2 - Answers✔Fluorite, CN = 8. Cation in every 2nd interstitial (AmXp)
Precipitation - Answers✔growing tiny second phase particles to strengthen material. Dislocations
are pinned by particles bc it takes more energy to go through a foreign particle
2
ALL RIGHTS RESERVED.
MSE 250 Final Exam Study Guide.
Liquidus line - Answers✔defines complete liquid )(above the line). First solid forms right below
it.
solvus line - Answers✔separates full solid from some liquid (solid below line)
eutectic reaction - Answers✔point where liquid and 2 solids are in equilibrium. Lowest melting
point
phase - Answers✔a region of a material that is chemically and physically uniform
The following can be determined from a phase diagram - Answers✔Phases present, composition,
melting temp, and amount of phases present.
TiNi3 Phase type - Answers✔intermetallic phase because it was 3Ni so it shows some nickel
stoichometry- suggests electron transfer
NiTi Phase type - Answers✔only says Ni & Ti coexist in the phase, doesn't say anything
chemically so it is intermediate phase. There's nothing to charge balance it so it can form many
crystal structures to be happier.
Eutectic transition - Answers✔liquid to solid (of 2 phases). L--> a + b
Congruent transition - Answers✔liquid to solid. L-->S of one phase
BCC Miller Indices - Answers✔Direction- [111], Planes- (110), no close packed planes
FCC Miller Indices - Answers✔Directions - [101],[110]. Planes - (1,-1,1)
HCP Miller Indices - Answers✔Directions - [100]. Planes - (001) or (000)
BCC Elements - Answers✔Iron, chromium, sodium, potassium
FCC Elements - Answers✔aluminum, copper, gold, nickel, and lead
HCP Elements - Answers✔cadmium, cobalt, titanium, zinc
Schotsky Ceramic Defect - Answers✔Cation and anion vacancy
1
, ©BRIGHTSTARS EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Frankel Ceramic Defect - Answers✔Cation moves and creates a vacancy, then it becomes an
interstitial to another cation
Creep - Answers✔deformation of static stresses examined at high temperatures
First stage of creep - Answers✔Primary - lots of dislocations as pull starts. Much strain in
response
Second stage of creep - Answers✔Secondary - steady strain rate as they get used to it
Third stage of creep - Answers✔Strain rate increases dramatically, too many dislocations (passed
equilibrium). Necting, rupture--> crack formation
3 creep mechanisms/causes - Answers✔diffusion of vacancies, dislocations, and grain
boundaries
Diffusion creep mechanism - Answers✔diffusion of vacancies - they move around. Bigger
grains, hard to move, so decreases diffusion. Longer diffusion paths
Dislocation creep mechanism - Answers✔creates strain hardening and dislocations.
Deformations are carried by dislocation motion. Climb via diffusion.
Grain boundary creep mechanism - Answers✔Prone to creep and cracks. They can grow into
obsesses as the boundaries slide
Screw verses edge dislocation - Answers✔Screw - parallel to bergers vector. Edge- perpendicular
to mergers vector.
Solid solution XX - Answers✔Alloying--add small atoms that pin dislocations. Small impurities
above slip planes, large below in region of tensile strains (think mass of item in water)
slip plane direction - Answers✔only happens in close packed planes
Fatigue limit - Answers✔
Rocksalt - Answers✔NaCl - CN = 6. Cations prefer octahedral sites.
CsCl - Answers✔Ceisum chloride. CN = 8. Cubic sites preferred
ZnS - Answers✔Zinc sulfide. CN = 4, cations occupy tetrahedral sites.
CaFa2 - Answers✔Fluorite, CN = 8. Cation in every 2nd interstitial (AmXp)
Precipitation - Answers✔growing tiny second phase particles to strengthen material. Dislocations
are pinned by particles bc it takes more energy to go through a foreign particle
2
