MATERIALS SCIENCE AND ENGINEERING
EXAM QUESTIONS WITH VERIFIED ANSWERS
allotropy - ANSWER elemental solids having more than one crystal structure
amorphous - ANSWER lacks arrangement of atoms (without form)
ansiotropy - ANSWER properties are dependent on direction
coordination number - ANSWER atoms touching unit cell. ex (FCC = 12)
(BCC = 8)
crystalline - ANSWER material's atoms are in repeating pattern or periodic
array over large atomic distnces
isotropic - ANSWER measured properties are independent of direction
7 crystal systems - ANSWER cubic, hexagonal, tetragonal, rhombohedral,
orthohombic, monoclinic, triclinic
polycrystalline - ANSWER crystaline solid composed of many small crystals
or grains
polymorphism - ANSWER when metals or nonmetals have more than one
crystal structure
point defects - ANSWER vacancies and self interstitials
solid solution rules (hume rothery) - ANSWER 1) same atomic size (within
%15)
2) same crystal structure
3) same electronegativity
4) same valences
weight percent - ANSWER [ m1 / (m1 +m2) ](x100)
, moles (n) - ANSWER atomic mass / atomic weight
linear defects (dislocations) - ANSWER edge and screw
interfacial defects - ANSWER mismatch between adjacent grains
solute - ANSWER The substance that is dissolved
solvent - ANSWER a liquid substance capable of dissolving other substances
anelasticity - ANSWER time depenent elasticity
resilience - ANSWER area under linear portion of curve (under yield point)
toughness - ANSWER area under entire curve (ultimate)
slip - ANSWER dislocation motion
strengthening mechanisms - ANSWER 1) solid solution ( alloying with
impurties = change in structure)
2) strain hardening (plastically deformed = cold working
3)grain size reduction (makes grain boundary smaller for dislocation motion)
eutectoid - ANSWER 1) one solid phase transforms to two other solid phases
2) all solid
eutectic - ANSWER When 2 solids are mixed together to form a liquid
peritectic - ANSWER liquid and one solid phase transform to a second solid
phase
homogeous nucleation - ANSWER nuclei form uniformly in substance
heterogeneous nucleation - ANSWER nuclei form at surface, on walls,
boundaries ect.
spheroidite heat treatment - ANSWER heat to just below eutectoid and hold
for long time (4 days)
EXAM QUESTIONS WITH VERIFIED ANSWERS
allotropy - ANSWER elemental solids having more than one crystal structure
amorphous - ANSWER lacks arrangement of atoms (without form)
ansiotropy - ANSWER properties are dependent on direction
coordination number - ANSWER atoms touching unit cell. ex (FCC = 12)
(BCC = 8)
crystalline - ANSWER material's atoms are in repeating pattern or periodic
array over large atomic distnces
isotropic - ANSWER measured properties are independent of direction
7 crystal systems - ANSWER cubic, hexagonal, tetragonal, rhombohedral,
orthohombic, monoclinic, triclinic
polycrystalline - ANSWER crystaline solid composed of many small crystals
or grains
polymorphism - ANSWER when metals or nonmetals have more than one
crystal structure
point defects - ANSWER vacancies and self interstitials
solid solution rules (hume rothery) - ANSWER 1) same atomic size (within
%15)
2) same crystal structure
3) same electronegativity
4) same valences
weight percent - ANSWER [ m1 / (m1 +m2) ](x100)
, moles (n) - ANSWER atomic mass / atomic weight
linear defects (dislocations) - ANSWER edge and screw
interfacial defects - ANSWER mismatch between adjacent grains
solute - ANSWER The substance that is dissolved
solvent - ANSWER a liquid substance capable of dissolving other substances
anelasticity - ANSWER time depenent elasticity
resilience - ANSWER area under linear portion of curve (under yield point)
toughness - ANSWER area under entire curve (ultimate)
slip - ANSWER dislocation motion
strengthening mechanisms - ANSWER 1) solid solution ( alloying with
impurties = change in structure)
2) strain hardening (plastically deformed = cold working
3)grain size reduction (makes grain boundary smaller for dislocation motion)
eutectoid - ANSWER 1) one solid phase transforms to two other solid phases
2) all solid
eutectic - ANSWER When 2 solids are mixed together to form a liquid
peritectic - ANSWER liquid and one solid phase transform to a second solid
phase
homogeous nucleation - ANSWER nuclei form uniformly in substance
heterogeneous nucleation - ANSWER nuclei form at surface, on walls,
boundaries ect.
spheroidite heat treatment - ANSWER heat to just below eutectoid and hold
for long time (4 days)
