Intro To AM Flashcards
What is additive manufacturing?
A range of manufacturing processes that create parts directly from CAD data in a layer by layer method
What are 4 current AM trends? And examples of what they entail
Patient specific prosthesis - 3D bio printing which is the combing of cells, growth factors and biomaterials to fabricate biomedical parts that naturally imitate tissue characteristics
Architecture - concrete 3d printer to build homes which runs on a set of tracks
Culinary - 3d printed doughs and proteins, the Chefjet is able to print objects using sugar
Historical - replicas of human remains and skeletons have been made using CT scans of originals
Why has the home printer market grown?
Wider range of materials available including carbon fibre
Patent expiry has allowed many machine builders to enter the market e.g the open source movement for FFF
Growth in material extrusion as you can now produce your own filament from recycled plastic bags etc
Availability of 3D printing resources such has CAD files has increased on open source websites so they can be accessed by the general public
Advantages of AM
AM offers greater geometric complexity over traditional processes
AM is very cost effective for low volume production
Current limitations of AM
Available material selection Material properties Resolution and surface finish Post processing Materials cost Throughput (time)
Why doesn’t every home have a 3D printer?
General public aren’t CAD savvy
Product safety, reliability and quality varies
Liability and copyright
What are some examples of companies and big brands using 3D printing?
Window have started to support plug in and go printing
NASA use SLM for difficult to fabricate parts
Adidas printed a shoe
Invisalign print braces
What are the 7 ASTM F42 process categories? And a description of each
Material extrusion - material selectively dispensed through a nozzle or orifice (FFF) Fused Filament Fabrication
Vat photopolymerisation - liquid photopolymer in a vat is selectively cured by light activated polymerisation (SLA) stereo lithography
Powder bed fusion - thermal energy selectively fuses regions of a powder bed (SLS) selective laser sintering
Material jetting - droplets of build material are selectively deposited (ink jet)
Binder jetting - a liquid bonding agent is selectively deposited to join powder materials (Zcorp 3d printing )
Directed energy deposition - focussed thermal energy is used to fuse materials by melting as the material is being deposited (LENS) laser engineered net shaping
Sheet lamination - sheets of material are bonded to form an object (UN)
What are the 5 AM steps for CAD to part?
CAD STL Setup build Manufacture component Post process
What does is do when converting a CAD file to an STL?
Tessellates the surface of the CAD model with an airtight mesh
What must be considered when setting up a print?
Part orientation Number of parts Process parameters Support structures Converting to GCODE
What can post processing include?
Powder removal
Support structure removal
UV curing
Infiltration of parts
What are the 5 main considerations for design for AM?
Layer direction affecting strength in certain axis
Angle or presence of overhangs
Supports on base and overhangs, can changing orientation reduce supports needed
STL deviation, smallest deviation results in the best quality print with large file size, large deviation gives a worse surface finish and poor quality print
Reducing mass/volume
What are 5 ways to reduce mass/volume in a print?
Use self supporting angles
Eliminate supports where possible
Low percentage infill speeds up printing, reduces warping and saves material
Hollowing out or adding a fill structure to parts
Consider tolerances and gaps
