Additive Manufacturing Flashcards
Define additive manufacturing according to ASTM. What’s another name for it?
a.Process of joining materials to make objects from 3D model data, usually layer
upon layer, as opposed to subtractive manufacturing methodologies, such as
traditional machining
b. 3D Printing, rapid prototyping, solid free-form fabrication
Define rapid prototyping and explain the process.
Another name for additive manufacturing; a set of technologies that produce
three-dimensional objects based on design data with the aid of a computer
What industries pioneered this technology?
Aerospace and automotive
Why has Rapid Prototyping spread into many other industries?
Expiration of Fused Deposition Modeling (FDM) patent in 2009
-Biomedical field in cell and tissue printing and orthopedics
Why is Rapid Prototyping important?
Product designers want to have a physical model of a new part or product design
i. Creating a prototype is an integral step in design
ii. A virtual prototype (a CAD model of the part) may not be sufficient for the
designer to visualize the part adequately
iii. Using RP to make the prototype, the designer can see and feel the part
and assess its merits and shortcomings
Name 2 RP technologies.
a. Material removal RP - machining, using a dedicated CNC machine, Starting
material is often wax
b. Material addition RP - adds layers of material one at a time to build the solid part
from bottom to top, Speed of part delivery, Complexity of part geometry is not an
issue in material addition RP
Summarize the RP process.
OR Outline the Additive Manufacturing process
Summarize the RP process.
a. Create a CAD Design
b. Optimized Model
c. Convert the CAD model to Stereolithography (STL) file.
d. Slice the STL file.
e. Convert it to G-Code for the 3D printer to understand
f. 3D-print the model
OR Outline the AM process.
g. Phase I: Design
i. CAD design
ii. .STL file
h. Phase II: Manufacturing
i. Slicer
ii. G-code
iii. 3D Printer
i. Phase III: Testing
i. 3D Object
Name three industries have developed AM applications?
a. Consumer production/electronics
b. Automotive
c. Medical/dental
d. Aerospace
e. Tools/molds
f. Other
What advantages does AM pose for medical applications?
a. 3D printing can be personalized to give back quality of life
What is the advantage for AM in part manufacturing?
a. Data exchange between development and production is quick/overnight
b. Ex: Adidas development in Germany, production in China
What are the advantages of AM?
a. Freedom of design
b. Freedom of fabrication time
c. Assist in prototyping
d. Waste reduction
e. Eliminate tooling
f. No storage cost
g. Increased employment opportunities
State the disadvantages of AM.
a. Intellecutal property issues
b. Limitation of size
c. Cost of printers (in the past, not now)
d. Unchecked production of dangerous items
e. Questionable accuracy
f. Support material removal
g. Limitations of raw material
h. Considerable effort required for application design and for setting process
parameters
i. Material cost
j. Material properties
Identify and draw a slice/layer of the solid model.
Look at the picture
(a) Conversion of a solid model of an object into layers
(b) Only one layer is shown
What is stereolithography (SL) and how is it accomplished?
a. RP process for fabricating a solid plastic part out of a photosensitive liquid
polymer using a directed laser beam to solidify the polymer
b. Part fabrication is accomplished as a series of layers - each layer is added onto
the previous layer to gradually build the 3-D geometry
T/F: Thicker layers provide better resolution and more intricate shapes, but processing
time is longer
False - the answers is thinner layers
What is selective laser sintering (SLS) and how is it accomplished?
a. Moving laser beam sinters heat-fusible powders in areas corresponding to the
CAD geometry model one layer at a time to build the solid part
b. Process:
i. After each layer is completed, a new layer of loose powders is spread
across the surface
ii. Layer by layer, the powders are gradually bonded by the laser beam into
a 3-D solid geometry
iii. In areas not sintered, the powders are loose and can be poured out of
completed part
What is 3-D printing (3DP) and how is it accomplished?
a. Part is built using an ink-jet printer to eject adhesive bonding material onto
successive layers of powders
b. Process:
i. Binder is deposited in areas corresponding to the cross sections of part,
as determined by slicing the CAD geometric model into layers
ii. The binder holds the powders together to form the solid part, while the
unbonded powders remain loose to be removed later
iii. To strengthen the part, a sintering step can be applied to bond the
individual powders
What is fused deposition modeling (FDM) and explain the process.
a. RP process in which a long filament of wax or thermoplastic polymer is extruded
onto existing part surface from a workhead to complete each new layer
b. Process:
i. Workhead is controlled in x-y plane during each layer and then moves up
by a distance equal to one layer in the z- direction
ii. Extrudate is solidified and cold welded to the cooler part surface in about
0.1 s
iii. Part is fabricated layer-by-layer from the base up
Name common starting materials:
a. Liquid monomers - cured layer by layer into solid polymers
b. Powders - aggregate and bonded layer by layer
c. Molten materials - solidified layer by layer
d. Solid sheets - laminated to create the solid part
Name 2 layer-forming processes:
a. Lasers
b. Printing heads that operate using ink-jet technology
c. Extruder heads
d. Other: Electron beams, UV light systems
Name 2 AM processes:
a. Liquid-based: Stereolithography and mask projection stereolithography
b. Powder-based: Selective laser sintering and three-dimensional printing
c. Molten material: Fused deposition modeling and droplet deposition
manufacturing
d. Solid-based: Laminated object manufacturing
Name 2 general FDM materials, 2 medical polymers for FDM, and 2 biodegradable and
biocompatible polymers
2 General FDM materials
a. ABS, PLA
2 Medical Polymers for FDM
b. Polyethylene, Polypropylene (PP), Polycarbonate (PC), Polyamide or nylon,
Polyester
2 Biodegradable and Biocompatible Polymers
c. PLA, PCL
What are some developing projects with biomedical applications?
a. Developing biodegradable, biocompatible SL 3D inks
b. 3D organ printing for tissue engineering
State 3 examples of 3D printing applications:
a. Pharmaceutical development
b. Organ & Tissue development
c. Dental Applications
d. Customizable prosthetics
