MSE 250 FINAL QUESTIONS AND CORRECT ANSWERS
liquidus line - ANSWER defines complete liquid )(above the line). First solid forms right
below it.
solvus line - ANSWER separates full solid from some liquid (solid below line)
eutectic reaction - ANSWER point where liquid and 2 solids are in equilibrium. Lowest
melting point
phase - ANSWER a region of a material that is chemically and physically uniform
The following can be determined from a phase diagram - ANSWER Phases present,
composition, melting temp, and amount of phases present.
TiNi3 Phase type - ANSWER intermetallic phase because it was 3Ni so it shows some
nickel stoichometry- suggests electron transfer
NiTi Phase type - ANSWER 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 - ANSWER liquid to solid (of 2 phases). L--> a + b
Congruent transition - ANSWER liquid to solid. L-->S of one phase
BCC Miller Indices - ANSWER Direction- [111], Planes- (110), no close packed planes
, FCC Miller Indices - ANSWER Directions - [101],[110]. Planes - (1,-1,1)
HCP Miller Indices - ANSWER Directions - [100]. Planes - (001) or (000)
BCC Elements - ANSWER Iron, chromium, sodium, potassium
FCC Elements - ANSWER aluminum, copper, gold, nickel, and lead
HCP Elements - ANSWER cadmium, cobalt, titanium, zinc
Schotsky Ceramic Defect - ANSWER Cation and anion vacancy
Frankel Ceramic Defect - ANSWER Cation moves and creates a vacancy, then it
becomes an interstitial to another cation
Creep - ANSWER deformation of static stresses examined at high temperatures
First stage of creep - ANSWER Primary - lots of dislocations as pull starts. Much strain in
response
Second stage of creep - ANSWER Secondary - steady strain rate as they get used to it
Third stage of creep - ANSWER Strain rate increases dramatically, too many
dislocations (passed equilibrium). Necting, rupture--> crack formation
3 creep mechanisms/causes - ANSWER diffusion of vacancies, dislocations, and grain
boundaries
Diffusion creep mechanism - ANSWER diffusion of vacancies - they move around. Bigger
liquidus line - ANSWER defines complete liquid )(above the line). First solid forms right
below it.
solvus line - ANSWER separates full solid from some liquid (solid below line)
eutectic reaction - ANSWER point where liquid and 2 solids are in equilibrium. Lowest
melting point
phase - ANSWER a region of a material that is chemically and physically uniform
The following can be determined from a phase diagram - ANSWER Phases present,
composition, melting temp, and amount of phases present.
TiNi3 Phase type - ANSWER intermetallic phase because it was 3Ni so it shows some
nickel stoichometry- suggests electron transfer
NiTi Phase type - ANSWER 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 - ANSWER liquid to solid (of 2 phases). L--> a + b
Congruent transition - ANSWER liquid to solid. L-->S of one phase
BCC Miller Indices - ANSWER Direction- [111], Planes- (110), no close packed planes
, FCC Miller Indices - ANSWER Directions - [101],[110]. Planes - (1,-1,1)
HCP Miller Indices - ANSWER Directions - [100]. Planes - (001) or (000)
BCC Elements - ANSWER Iron, chromium, sodium, potassium
FCC Elements - ANSWER aluminum, copper, gold, nickel, and lead
HCP Elements - ANSWER cadmium, cobalt, titanium, zinc
Schotsky Ceramic Defect - ANSWER Cation and anion vacancy
Frankel Ceramic Defect - ANSWER Cation moves and creates a vacancy, then it
becomes an interstitial to another cation
Creep - ANSWER deformation of static stresses examined at high temperatures
First stage of creep - ANSWER Primary - lots of dislocations as pull starts. Much strain in
response
Second stage of creep - ANSWER Secondary - steady strain rate as they get used to it
Third stage of creep - ANSWER Strain rate increases dramatically, too many
dislocations (passed equilibrium). Necting, rupture--> crack formation
3 creep mechanisms/causes - ANSWER diffusion of vacancies, dislocations, and grain
boundaries
Diffusion creep mechanism - ANSWER diffusion of vacancies - they move around. Bigger
