Page 1 of 16
MECH502 FINAL EXAM QUESTION AND VERIFIED ANSWERS GRADED TO PASS
100% 2026 – 2027.
In powder-bed fusion, a "Melt Flow Index" is used to help determine...
If powder is reusable
The slope of a photopolymer's working curve represents...
The distance a given irradiance will decrease by an amount equal to the half-width of the gaussian,
as it penetrates a given photopolymer
Your boss emails you the following picture and asks you how it was made using additive
manufacturing. He is amazed that the object is 10 µm long and 7 µm high, made of urethane
acrylate. What is most likely the AM process used to make this part?
Two-photon photopolymerization
Your colleague asks you which AM process was most likely used to make this object. It has a
rough, grainy surface that appears to have been post-processed with a coating that gives it the shine
you see. What do you tell her? (see heart model image on desktop)
Binder jetting
Your colleague asks you which AM process was most likely used to make this object. He tells you
it's made of fully dense titanium and has a rough, grainy surface. What do you tell him?
Powder bed fusion
Your colleague asks you which AM process was likely used to make this object. You can easily
see its corrugated, shiny surface that the technician says is direct from the printer (i.e. there was
no post-processing on these parts), and your analysis lab says the parts are fully-dense. What do
you tell her? (see boeing image on desktop)
Directed energy deposition
Which type of sintering is characterized by the coalescence of powder particles of more than one
material without full melting?
All of the above: Indirect sintering, liquid phase sintering, chemically-induced sintering
cost of ownership
true cost - install +mat'l + initial cost+ disposale
buid vol vs bounding box
build vol - max size of printable volume for printbounding box - smallest box size to fit a part
inside
curing time
, Page 2 of 16
The terms "precision" and "resolution" are used interchangeably to refer to:
The smallest feature that a particular 3D printer can print, independent of any particular material.
Which set of characteristics provides the best list of the things to consider when deciding which
additive process to use to make a particular part?
Purpose of part (e.g. functional requirements), material requirements, size of part
Which set of metrics lists two of the most important considerations when deciding to make a
product using additive manufacturing, or if subtractive or formative manufacturing may be a
better choice?
Cost per complexity, Cost per quantity
True or False: Bioprinting usually uses a jetting process with a very fine spray of material.
False
In the context of 3D digital modeling, what is a "manifold" model?
A model that is completely closed between the inside of the model and the outside. If it were a
physical object, it could hold water.
The term "Dynamic precision" refers to...
A measure of the smallest feature a particular printer can create with its most accurate material,
all other factors being held constant
The name of the additive manufacturing process in which a liquid bonding agent is selectively
deposited to join powder material is:
Binder jetting
Which of the following terms is used to characterize the difference between the dimensions of an
as-printed part and the dimensions of a digital, as-designed (CAD) part?
accuracy
Laser melting is a type of which of the following additive processes?
Powder Bed Fusion
Which additive process involves the use of light to cure/harden a liquid polymer?
Photopolymerization
Considering the process parameters controlling material flow in melt extrusion-based systems, if
you want to minimize the attachment/adhesion of support material at the interface regions
(between model and support material), assuming primary support material, the best approach
would be:
, Page 3 of 16
Make print/scan speed faster when printing the interface regions than when printing anything
else, all other parameters stay the same
True or False: Hot iso-static pressing (HIP) is a method for densifying metal parts created with
powder-based fusion processes.
True
The length of time it takes for paint or varnish to "set" or reach its ultimate, stable state.
foam vs lattice structure
random, stoic
-controllable
- stucture width posisty and heights etc
- known stress strin curve to FEA
Bulk vs structural properties
bulk - raw materials
structure - properties of mat'l's structure
Extrusion Based Systems
Extrusion
- like forming modular t slot
melt extrusion
"ram" - lost cost, low precision
head - feed controlled 1) screw extrusion 2) ram 3) gas pressure
head weights and build size effect of precision
How filament made?
helical worm gear -> compression -> filament out -> buy -> print
MECH502 FINAL EXAM QUESTION AND VERIFIED ANSWERS GRADED TO PASS
100% 2026 – 2027.
In powder-bed fusion, a "Melt Flow Index" is used to help determine...
If powder is reusable
The slope of a photopolymer's working curve represents...
The distance a given irradiance will decrease by an amount equal to the half-width of the gaussian,
as it penetrates a given photopolymer
Your boss emails you the following picture and asks you how it was made using additive
manufacturing. He is amazed that the object is 10 µm long and 7 µm high, made of urethane
acrylate. What is most likely the AM process used to make this part?
Two-photon photopolymerization
Your colleague asks you which AM process was most likely used to make this object. It has a
rough, grainy surface that appears to have been post-processed with a coating that gives it the shine
you see. What do you tell her? (see heart model image on desktop)
Binder jetting
Your colleague asks you which AM process was most likely used to make this object. He tells you
it's made of fully dense titanium and has a rough, grainy surface. What do you tell him?
Powder bed fusion
Your colleague asks you which AM process was likely used to make this object. You can easily
see its corrugated, shiny surface that the technician says is direct from the printer (i.e. there was
no post-processing on these parts), and your analysis lab says the parts are fully-dense. What do
you tell her? (see boeing image on desktop)
Directed energy deposition
Which type of sintering is characterized by the coalescence of powder particles of more than one
material without full melting?
All of the above: Indirect sintering, liquid phase sintering, chemically-induced sintering
cost of ownership
true cost - install +mat'l + initial cost+ disposale
buid vol vs bounding box
build vol - max size of printable volume for printbounding box - smallest box size to fit a part
inside
curing time
, Page 2 of 16
The terms "precision" and "resolution" are used interchangeably to refer to:
The smallest feature that a particular 3D printer can print, independent of any particular material.
Which set of characteristics provides the best list of the things to consider when deciding which
additive process to use to make a particular part?
Purpose of part (e.g. functional requirements), material requirements, size of part
Which set of metrics lists two of the most important considerations when deciding to make a
product using additive manufacturing, or if subtractive or formative manufacturing may be a
better choice?
Cost per complexity, Cost per quantity
True or False: Bioprinting usually uses a jetting process with a very fine spray of material.
False
In the context of 3D digital modeling, what is a "manifold" model?
A model that is completely closed between the inside of the model and the outside. If it were a
physical object, it could hold water.
The term "Dynamic precision" refers to...
A measure of the smallest feature a particular printer can create with its most accurate material,
all other factors being held constant
The name of the additive manufacturing process in which a liquid bonding agent is selectively
deposited to join powder material is:
Binder jetting
Which of the following terms is used to characterize the difference between the dimensions of an
as-printed part and the dimensions of a digital, as-designed (CAD) part?
accuracy
Laser melting is a type of which of the following additive processes?
Powder Bed Fusion
Which additive process involves the use of light to cure/harden a liquid polymer?
Photopolymerization
Considering the process parameters controlling material flow in melt extrusion-based systems, if
you want to minimize the attachment/adhesion of support material at the interface regions
(between model and support material), assuming primary support material, the best approach
would be:
, Page 3 of 16
Make print/scan speed faster when printing the interface regions than when printing anything
else, all other parameters stay the same
True or False: Hot iso-static pressing (HIP) is a method for densifying metal parts created with
powder-based fusion processes.
True
The length of time it takes for paint or varnish to "set" or reach its ultimate, stable state.
foam vs lattice structure
random, stoic
-controllable
- stucture width posisty and heights etc
- known stress strin curve to FEA
Bulk vs structural properties
bulk - raw materials
structure - properties of mat'l's structure
Extrusion Based Systems
Extrusion
- like forming modular t slot
melt extrusion
"ram" - lost cost, low precision
head - feed controlled 1) screw extrusion 2) ram 3) gas pressure
head weights and build size effect of precision
How filament made?
helical worm gear -> compression -> filament out -> buy -> print
