CHAPTER
14
÷
SOLID
FREEFORM
FABRICATION
ELECTRON
BEAM
MELTING
→
obxots
one
made
layer
SFF
is
an
additive
manufacturing
technique
to
create
by
layer
by
melting
complex
objects
in
a
layer
by
layer
manner
.
metal
powder
with
an
1.
Creation
of
a
CAD
model
electron
beam
in
a
vacuum
2.
Conversion
of
the
CAD
model
to
STL
format
chamber
3.
Slicing
the
STL
file
into
thin
cross-sectional
layers
so
Full
melting
of
the
G.
Construction
of
the
model
layer
by
layer
metal
powder
is
achieved
.
5.
Cleaning
G
finishing
.
STEREO
LITHOGRAPHY
→
The
model
is
built
upon
a
platform
contained
in
a
vat
of
liquid
resin
.
÷÷±÷÷÷÷÷
:*
:*
MM
2.
The
elevator
stage
lowers
3.
Other
layer
is
made
as
the
previous
one
4.
A
sweeper
reooats
the
solidified
layer
'
with
liquid
so
the
laser
can
trace
the
other
one
atop
the
previous
.
5.
The
process
continues
until
the
last
layer
is
made
.
DIRECT
METAL
LASER
SINTERING
→
It
uses
a
precise
,
high
melt
age
laser
to
micro
Weld
powdered
metals
as
complex
geometries
can
be
made
[
"
"
"
"
"
"
"
"
÷i÷÷÷::÷÷÷÷÷÷:÷÷
:÷÷÷÷i:÷:÷:÷÷÷
:÷÷::±:÷÷÷÷÷:÷:÷÷
:i÷÷÷:÷÷÷÷::÷÷
:÷÷÷÷÷÷÷÷÷::÷÷÷
:÷÷i:÷
-
Field
of
view
-
section
thickness
-
Rotation
feed
-
Interstice
thickness
-
Reconstruction
algorithm
-
Gantry
tilt
.
Sliced
2D
images
one
obtained
.
2.
surface
generation
stage
:
process
is
carried
out
on
dedicated
software
s
(
MIMICS
)
.
3D
PRINTING
on
shooting
deep
lots
of
liquid
-
to
-
solid
Errors
can
arise
due
to
the
compound
and
create
a
layer
of
the
selection
of
a
proper
threshold
:
object
.
the
choice
is
done
relying
on
2.
Inkjet
printing
head
selectively
prints
Hours
field
Unit
of
the
tissue
binder
to
fuse
powder
in
the
desired
to
be
modelled
.
area
.
The
solution
is
to
use
local
2.
The
platform
is
lowered
,
more
powder
thresholds
for
different
regions
is
added
and
leveled
.
oe
the
model
.
3.
Process
is
repeated
.
image
segmentation
by
threshold
is
used
to
define
region
of
interest
CR01
)
.
3.
3-D
reconstruction
stage
:
region
growing
technique
puts
together
the
Rot
to
reconstruct
the
3D
model
4.
Anatomical
model
manufacturing
via
SFF
stage
.
Reverse
engineering
can
be
applied
to
reconstruct
maxillary
bone
,
to
treat
ballistic
trauma
oe
hemi
facial
micro
somia
.
HOUNS
FIELD
UNIT
=
quantity
used
in
CT
scanning
in
oedee
to
express
CT
numbers
in
a
standardized
foem
.
Obtained
from
a
linear
transformation
of
the
measured
attenuation
coefficients
.
-
