Additive Manufacturing Exam 1 UPDATED
ACTUAL Questions And CORRECT
Answers
Metal Additive Manufacturing Methods - CORRECT ANSWER - Power bed Fusion
Directed Energy Deposition
Laser-based methods
Laser-based Metal AMM - CORRECT ANSWER - Selective Laser Melting (Laser-
Powder Bed Fusion)
Laser-engineered Net Shaping (Direct Laser Deposition)
Benefits of AMM - CORRECT ANSWER - create 'tailored' properties
customize parts for specific applications
fabricate complex geometries (convert assemblies to integrated parts, fabricate parts on demand,
reduce overall time weight and cost of parts), repair expensive parts, manufacture in remote
locations (strategic remote supply line, remote mining, space exploration)
Challenges of AMM - CORRECT ANSWER - parts prone to having porosity and
imperfections
structural integrity of parts unknown
minimal standards and regulation for production and end-parts
certification needed
demand for AM-trained workforce
industry-wide hesitation
Challenges of Metal AMM - CORRECT ANSWER - shorter fatigue life (process-induced
defects)
powder quality
,proper post-processing methods (heat treatment)
anisotropy and build orientation
surface roughness
time interval, geometry, and size effect
shielding gas
Fatigue life - CORRECT ANSWER - point at which the material fails (stress v failure and
strain v failure)
much shorter fatigue lives for AM
cracks initiate near surface defects
powder quality - CORRECT ANSWER - powder quality and number of times recycled
effects fatigue life
production using used powder produces better fatigue resistance
heat treatment - CORRECT ANSWER - does not improve long term fatigue resistance
needs revision for AM parts
anisotropy - CORRECT ANSWER - build orientation
more stable to build horizontally compared to vertically
dependent on material and equipment
works against AM goal to reduce post-processing
surface area/roughness - CORRECT ANSWER - affects fatigue life
larger surface area results in lower roughness and improved fatigue resistance
time interval, size and geometry - CORRECT ANSWER - structure-property and property-
performance relationships must be established
size of part affects thermal history and microstructure and mechanical properties
, temperature response and cooling rate dependent on part size and shape
optimal parameters don't provide similar thermal histories for various sized components
shielding gas - CORRECT ANSWER - during fabrication, flows in same direction as laser
movement pushing preheated gas to the front of the melt pool, decreasing temperature gradient
results in variations in residual stress and/ microstructure
EES - CORRECT ANSWER - Electrical Energy Storage Systems
Critical factors for designing EES - CORRECT ANSWER - ability to store energy
cost effective
ability to store power
long lifetime
safe to use
types of energy storage devices - CORRECT ANSWER - batteries (Li-ion)- chemical
reaction
electrochemical capacitors (electric double layer capacitor)- physical reaction
advantages and disadvantages of batteries - CORRECT ANSWER - advantages:
high energy density
disadvantages:
diffusion limited
low power
limited lifetime
advantages and disadvantages of EDLC - CORRECT ANSWER - advantages:
fast charge and discharge rates
ACTUAL Questions And CORRECT
Answers
Metal Additive Manufacturing Methods - CORRECT ANSWER - Power bed Fusion
Directed Energy Deposition
Laser-based methods
Laser-based Metal AMM - CORRECT ANSWER - Selective Laser Melting (Laser-
Powder Bed Fusion)
Laser-engineered Net Shaping (Direct Laser Deposition)
Benefits of AMM - CORRECT ANSWER - create 'tailored' properties
customize parts for specific applications
fabricate complex geometries (convert assemblies to integrated parts, fabricate parts on demand,
reduce overall time weight and cost of parts), repair expensive parts, manufacture in remote
locations (strategic remote supply line, remote mining, space exploration)
Challenges of AMM - CORRECT ANSWER - parts prone to having porosity and
imperfections
structural integrity of parts unknown
minimal standards and regulation for production and end-parts
certification needed
demand for AM-trained workforce
industry-wide hesitation
Challenges of Metal AMM - CORRECT ANSWER - shorter fatigue life (process-induced
defects)
powder quality
,proper post-processing methods (heat treatment)
anisotropy and build orientation
surface roughness
time interval, geometry, and size effect
shielding gas
Fatigue life - CORRECT ANSWER - point at which the material fails (stress v failure and
strain v failure)
much shorter fatigue lives for AM
cracks initiate near surface defects
powder quality - CORRECT ANSWER - powder quality and number of times recycled
effects fatigue life
production using used powder produces better fatigue resistance
heat treatment - CORRECT ANSWER - does not improve long term fatigue resistance
needs revision for AM parts
anisotropy - CORRECT ANSWER - build orientation
more stable to build horizontally compared to vertically
dependent on material and equipment
works against AM goal to reduce post-processing
surface area/roughness - CORRECT ANSWER - affects fatigue life
larger surface area results in lower roughness and improved fatigue resistance
time interval, size and geometry - CORRECT ANSWER - structure-property and property-
performance relationships must be established
size of part affects thermal history and microstructure and mechanical properties
, temperature response and cooling rate dependent on part size and shape
optimal parameters don't provide similar thermal histories for various sized components
shielding gas - CORRECT ANSWER - during fabrication, flows in same direction as laser
movement pushing preheated gas to the front of the melt pool, decreasing temperature gradient
results in variations in residual stress and/ microstructure
EES - CORRECT ANSWER - Electrical Energy Storage Systems
Critical factors for designing EES - CORRECT ANSWER - ability to store energy
cost effective
ability to store power
long lifetime
safe to use
types of energy storage devices - CORRECT ANSWER - batteries (Li-ion)- chemical
reaction
electrochemical capacitors (electric double layer capacitor)- physical reaction
advantages and disadvantages of batteries - CORRECT ANSWER - advantages:
high energy density
disadvantages:
diffusion limited
low power
limited lifetime
advantages and disadvantages of EDLC - CORRECT ANSWER - advantages:
fast charge and discharge rates
