It gives complete information about additive manufacturing/3D printing- types of 3D printing processes and metallic 3D printing.

1. Presented by
N.SUDHEER
M.TECH(MACHINE DESIGN)
16481D1509
GUDLAVALLERU ENGINEERING COLLEGE
Sheshadri Rao Knowledge Village, Gudlavalleru,PIN:521356.
A technical seminar on

2. Additive manufacturing??
Additive manufacturing or 3D printing is a process
of making three-dimensional solid objects from a
digital model.

3.  Subtractive manufacturing is a process by which 3D objects are
constructed by successively cutting material away from a solid block of
material. It is also known to us as “Conventional manufacturing”.
 Additive Manufacturing is a process by which 3D objects are
constructed by successively depositing material in layers such that it
becomes a predesigned shape.
Modern 3D printing has always been very useful for rapid prototype
development but it is starting to make its impact on the manufacturing
world as well.

4. A prototype is an early sample, model, or release of a
product built to test a concept or process to estimate the
behavior of original product under working conditions.
 Rapid prototyping(RP) is a group of techniques used to
quickly fabricate a scale model of a physical part or assembly
using three-dimensional computer aided design (CAD) data.

5. oCreate a CAD model of the design
oConvert the CAD model to STL format
oSlice the STL file into thin cross-sectional layers
oConstruct the object through layer by layer
oClean and finish the object if may required

6. Digital object storage
More local manufacturing
Reduced materials wastage
Increased customization
Reduction of product development time
Complexity is free
Little-skill manufacturing
No assembly required
Tool less
Extreme light weight design
Increased employment opportunities in design field.

7. Slow build rates
High production costs
Extensive knowledge in material design
Limited component size/ small build volume
Poor mechanical properties.

8. This timeline lays out past, present and potential future AM
developments and applications.
(From Royal Academy of Engineering- UK )

9. Over the last years became valid for the for the whole life cycle of
the product.
Idea

12. Fig: Hopkinson and Dickens (2003) Cost Model Compared to
Injection Molding

13. Fig: Classification of AM processes

14. It is the first and foremost 3D printing process.
SL is a laser-based process that works on the photo polymerization.
Photo polymerization reactions are chain-growth polymerizations
which are initiated by the absorption of visible or ultraviolet light.
The light may be absorbed either directly by the reactant monomer
(direct photo polymerization), or else by a photo sensitizer which
absorbs the light and then transfers energy to the monomer.

16. Stereo lithography (SL) prototypes are constructed from a liquid
photopolymer that is selectively cured using a solid-state laser.
The process begins with a 3D CAD file, which is mathematically sliced
into 2D cross sections.
With the build platform positioned just below the surface of the
photopolymer, a scanning system is used to draw the first cross section on
the surface of the photopolymer, which adheres to the platform.
When the layer is complete, the elevator assembly lowers the platform
into the vat and the next layer is drawn, with each new layer adhering to
the previous one.
The process repeats itself until the object is completed.
Actual build times can range from under an hour to over a day,
depending on the photopolymer, laser power, and the object geometry.

17. Prototypes for design, analysis, verification and functional
testing.
Parts for prototype tooling and low volume production tooling.
Patterns for investment casting, sand casting and molding.
Models for conceptualization and presentation.

18. Procedure:
The SLS process creates 3D objects, layer by layer, from CAD-
data using powdered materials with heat generated by CO2 laser
within the sinteration system.
CAD data files in the .STL format are first transferred to the
sinteration systems where they are sliced.
From this point, the SLS process begins and operate as follows:

19. 
Fig: SLS process

20. The interaction of the laser beam with the powder elevates the
temperature to the point of melting, fusing the powder particles
to form a solid mass.
The intensity of laser beam is modulated to melt the powder
only in areas defined by the part’s geometry.
Surrounding powder remains a loose compact and serves as
natural supports.
When the cross-section is completely “drawn”, an additional
layer of powder is deposited via a roller mechanism on top of the
previously scanned layer.
This prepares the next layer for scanning.
By successive layers of powder deposition, the process is
repeated until the part is completed.

21. Concept models: Physical representation of designs used to
review design ideas, form and style.
Functional models and working prototypes: Parts that can
withstand limited functional testing, or fit and operate within an
assembly.
Polycarbonate patterns(rapid casting): These patterns are
used in investment casting process rather than wax patterns.
These patterns are durable and heat resistant.
Metal tools: direct rapid prototype of tools of molds for small
and short production runs.

22. The principle of the FDM process is based on the surface
chemistry, thermal energy and layer manufacturing technology.
The material in filament form(or unwounded or uncoiled metal
wire form) is melted in a specially designed head, which extrudes
it through the nozzle.
As it is extruded, it is cooled and thus solidifies to for the
object.
The object is built layer by layer, like the other RP systems.

24. Aerospace
Prototyping
Automotive
Medical Instruments/ Surgical Implants
Research & Development
Dental
Art/Jewelry

25. Fig: High strength thermoplastic 3D printing

26. Fig: Metal 3D printing

27. 1. Rapid Prototyping: principles and applications- Rafiq.I.Noorani(John Wiley&
sons publishers).
2. Rapid Prototyping: principles and applications- C.K.Chua, K.F.Leong &
C.S.Lim (Cambridge University press)-3rd edition.
3.Additive manufacturing- Amit Bandyopadhyay & Susmita Bose (CRC press).
4.3D printing: The Next Industrial Revolution-Christopher Barnatt (published by
“Explaining The Future.com”)-2nd edition.
5. https://www.3dsystems.com/
6. http://www.harbec.com/
7. http://www.raeng.org.uk/
8. http://www.nature.com/
9. https://www.creativemechanisms.com/
10. http://www.incodema3d.com/
11. http://additivemanufacturing.com/basics/

28. Thank you