Fabrication is the processing of raw material or any semi finished product in the final shape by different methods such as welding, forming, sheet metal operations or casting. Solid Freeform Fabrication (SFF) is related to rapid prototype process.

2.  Let us define the term Fabrication:
Fabrication is the processing of raw material
or any semi finished product in the final
shape by different methods such as welding,
forming, sheet metal operations or casting.
 Solid Freeform Fabrication (SFF) is related
to rapid prototype process.

3.  A physical prototype is built, in order to test
various aspects of design, illustrate ideas
before any production process.
 This type of prototype is mainly made on lathe
or milling machines and are termed as
subtractive methods.
 For complex shapes subtractive method is
difficult to create and time consuming.
 So, Rapid Prototyping is used as an
alternative method to subtractive method, in
which they add and bond materials in the form
of layers

5. 1984 - 86
Charles Hull invents 3D printing and coins
the term “Stereo Lithography”
1992
First 3D printer built by 3D Systems
1999
First application of 3D printing in the medical field
- creating the human bladder

6.  Definition: Solid freeform fabrication (SFF) refers
to a category of manufacturing processes in which
parts are built by depositing one cross-sectional
layer of material on top of the next. It is very much
like "printing" a succession of slice images one on
top of the next so that thickness is gradually built
up.

8.  Following techniques are mostly used for
solid freeform fabrication
1. Stereolithography apparatus (SLA)
2. Fused Deposition Modelling (FDM)
3. Selective laser sintering (SLS)

9.  In this technique a UV light source scans a photosensitive
polymer which partially cures under the energetic light
source. After each layer is formed, the elevator is lowered
to allow uncured liquid to flow over the top of the part, in
preparation for scanning the next layer features. Post
curing following laser scanning of the entire part completes
the production cycle.

10.  A SFF process in which thermoplastic
precursor material is heated and extruded
from a head carried on an XYZ table to
produce a 3-D part

11.  Pre-processing: Build-preparation software slices
and positions a 3D CAD file and calculates a path
to extrude thermoplastic and any necessary support
material.
 Production: The 3D printer heats the thermoplastic
to a semi-liquid state and deposits it in ultra-fine
beads along the extrusion path. Where support or
buffering is needed, the 3D printer deposits a
removable material that acts as scaffolding.
 Post-processing: The user breaks away support
material or dissolves it in detergent and water, and
the part is ready to use.

13.  The use of a Computer-controlled,. High-power laser to
melt or sinter powder together is the basis for University of
Texas developed DTM Corporation's Selective Laser
Sintering (SLS) system.
 A thin layer of powder is spread over a base and a laser
selective scans the powder bed, sintering or melting the
material together.
 The base is lowered slightly, a new layer of powder is
spread over the selectively sintered layer, and laser scans
again, this time selectively sintering or melting powder
together into the preceding layer.
 The process is continued to generate a complete part.

16.  Traditional Manufacturing
 Solid Freeform Fabrication

17. 1. Making core for sand casting
2. In various implants of different organs in
human body

18.  There are two SFF applications in sand casting
pattern making and core making.
 Patterns are used to form the imprint in the sand
mold.
 Core arrays form the internal cavities or
passageways of cast metal parts, such as internal
geometries of engine blocks.
 In conventional core making, cores are fabricated in
many pieces that would have to be assembled with
core paste and placed in the mold and gauged for
accuracy of fit. Cored holes and features are
usually limited to ¼”diameter.

20.  Scientists, including an Indian-
origin researcher, have created a
3D-printed bionic ear that can
"hear" radio frequencies far
beyond the range of normal
human capability. Using off-the-
shelf printing tools, the scientists
at Princeton University explored
3D printing of cells and nano
particles, creating the bionic ear.

21. 1. http://nptel.ac.in/courses/112102103/16
2. http://www.srl.gatech.edu/education/ME6105/Projects/Fa11/rapidprototypi
ng/
3. http://www.inventionpartner.com/rapid-prototyping-processes.html
4. McGraw-Hill Machining and Metalworking Handbook, Third Edition
5. Advances in Multiple Material Solid Freeform Fabrication, Richard H.
Crawford, Joseph J. Beaman, David L. Bourell, and Kristin L. Wood,
Laboratory for Freeform Fabrication, The University of Texas at
Austin,2001
6. Solid Freeform Fabrication An Advanced Manufacturing Approach, D.L.
Bourell, J.J. Beaman, H.L. Marcus, J.W. Barlow
7. Louhbourough University 2000
8. Solid Freeform Fabrication, IEEE Spectrum 1999
9. https://medecms.gov.mt/en/resources/News/Documents/Youth%20Guaran
tee/3D%20Printing.pdf
10. http://www.dtic.mil/dtic/tr/fulltext/u2/a274552.pdf

22. Thank You