additive manufacturing Flashcards
(19 cards)
3 ways in which AM methods can be categorised in terms of layer-based approach
- different materials of the layers
- the way the layers are created
- the way the layers are bonded
What do the different AM layer-based approaches determine?
- accuracy
- cost of machine and process
- material
- mech properties
- how much post-processing is required
- how quickly the part can be made
- the size of the AM machine used
what are enabling technologies
equipment and/or methodology that, alone or in combination with associated technologies, provides the means to generate giant leaps in performance and capabilities
what is needed for AM
- computers
- CAD (or 3D/MRI scanners if already made)
- control systems
- energy source (UV/laser/electron beam)
what is hybrid manufacturing
the combination of both subtractive and additive manufacturing methods to utilise the benefits of both technologies.
First build the less complex section of part using subtractive (eg CNC) and the more complex sections of the part with additive
advantages of hybrid manufacturing
considerations of hybrid parts
need to consider;
- joint strength
- mech properties (eg tensile strength)
- fatigue life
What is additive manufacturing?
the process by which 3D design data is used to build up a component in layers by depositing material
what is rapid prototyping?
aka 3D printing. RP is the old name for AM.
process whereby a system/part representation is rapidly created before final release/commercialisation
pros of RP
- design evaluation
- trouble shooting before production
- produced before allocating large amounts of capital
use of AM parts
to make physical models to evaluate manufacturability and design effectiveness. these models provide info on the 3 Fs.
3 Fs of AM
FORM: the shape and general purpose of the design
FIT: the improved accuracy of AM allows components to be built to the required tolerances for assembly
FUNCTION: can obtain improved material properties with AM so parts can be properly handled and assessed according to their intended application
basic principle of AM technology
a model is initially generated using a 3D CAD system and can be fabricated directly without the need for process planning.
why is AM the preferred tech to produce complex 3D objects directly from CAD data?
other manufacturing processes require a careful and detailed analysis of the part geometry to determine things like the order in which different features can be fabricated; what tools and processes must be used; and what additional fixtures may be required to complete the part
simple way to test AM machine is still operating within acceptable limits
using a test pattern periodically; provided by the machine vendor
why do AM materials need to be handled with care?
- some of the AM raw materials have limited shelf-life
- may also require being kept in conditions that prevent them from unwanted chemical reactions
- should avoid exposure to moisture, excess light and other contaminants
2 VAT polymerisation techniques
Stereolithography (SLA)
Digital Light Prototyping (DLP)
material used in VAT polymerisation techniques
light curable resin
Why is a vacuum needed in EBM?
- To reduce the chances of electrons deflected by the atmospheric atoms, molecules, particles etc, thereby saving energy and increasing the heat accumulation at the melting zone.
- To reduce the possibilities of arcing.
- To maintain the required material compositions and minimise the chances of undesired material infiltration
