INGENIEUR
Results
Results and
and Discussion
Discussion
This
This section
section covers
covers the
the results
results and
and discussion
discussion of
of
the
the effect
effect of
of machining
machining parameters
parameters on
on machining
machining
performance
performance. (Jahan
(Jahan et et al. ,
al., 2008).
2008). The
The data
data value
value
of
MRR
was
calculated
by
collecting
the
data
o f M R R w a s c a l c u l a t e d b y c o l l e c t i n g t h e d a t a from
f r o m
differences
differences in
in weight
weight of
of several
several work-pieces
work-pieces before
before
and
and after
after hole
hole fabrication
fabrication and
and machining
machining time.
time. The
The
data
data value
value of
of EWR
EWR was
was calculated
calculated by
by collecting
collecting the
the
data
from
the
difference
in
weight
of
an
electrode
data from the difference in weight of an electrode
and
a a work-piece.
and
work-piece.
of MRR
against against
Workpiece
6: Graph
Figure
6: Graph of MRR against Workpiece Figure
Figure 7: 7:
Graph
of MRR
Workpiece Figure 7: G
Thickness
Material
Thickness
Material
Thickness
Material
Material Removal
Removal Rate
Rate (MRR)
(MRR)
MRR
MRR refers
refers to
to the
the weight
weight loss
loss of
of work-piece
work-piece at
at the
the
end
end of
of the
the micro-EDM
micro-EDM process.
process. The
The results
results of
of the
the
graphs
graphs (Figures
(Figures 6 6 – – 10)
10) show
show that:
that:
● ●
MRR
MRR decreases
decreases with
with the
the change
change of
of work-
work-
piece
material
from
brass
to
stainless
steel.
piece material from brass to stainless steel.
● ●
MRR
MRR decreases
decreases linearly
linearly to
to the
the work-piece
work-piece
thickness.
thickness.
● ●
MRR
MRR first
first has
has a a slight
slight decrease
decrease followed
followed
by
a
linear
increase
with
an
increase
by a linear increase with an increase in
in
electrode
electrode diameter.
diameter.
Figure 6: Graph
of MRR
against
Workpiece
Figure against
7: Graph
of MRR against W
Graph
of MRR
against
Electrode
Figure
6:
of
Figure
Graph
of of
● ●
MRR
is
proportional
nominal
MRR
is directly
directly
proportional
to Workpiece
nominal Figure
8:
Graph
MRR
Electrode
Figure
8: Graph
Graph
of MRR
MRR against
against to
Electrode
Figure 8: 7:
9:
of MRR
MRR against
against Workpiece
Nominal Figure 9: G
Material
Thickness
Diameter
Material
Thickness
capacitance
Diameter
Capacitance
capacitance applied.
applied.
Diameter
Capacitance
● ●
MRR
first
has
a
slight
decrease
followed
MRR
have a slight decrease followed
by
by a a linear
linear increase
increase when
when the
the feed
feed rate
rate is
is
increasing.
increasing.
Brass
Brass is
is a a more
more favourable
favourable work-piece
work-piece material
material
for
for machining
machining using
using micro-EDM
micro-EDM as
as the
the melting
melting
point
point of
of brass
brass (930
(930 o o C)
C) is
is lower
lower than
than the
the melting
melting
point
point of
of stainless
stainless steel
steel (1510
(1510 o o C).
C). Hence,
Hence, more
more
material
can
be
melted
and
evaporated
in
material can be melted and evaporated in the
the
micro-EDM
micro-EDM process
process (Yu
(Yu et
et al.,
al., 1998).
1998). Therefore,
Therefore,
the
the MRR
MRR is
is higher
higher for
for a a brass
brass work-piece.
work-piece. With
With an
an
Figure against
8: Graph
of MRR
against
Electrode
Figure Nominal
9: 10:
Graph
of
MRR against
against
Figure
9: 9:
Graph
of MRR
against
Figure 8:
Graph of thickness,
MRR
Electrode
Figure
Graph
against
Nominal
Graph
of MRR
Fe
increase
in
more
thermal
increase
in work-piece
work-piece
thickness,
more
thermal
Figure 10: Graph of MRR
against
Feed
Rate of MRR Figure
Diameter
Capacitance
Capacitance
Diameter
Capacitance
Figure
10:
Graph
of of
MRR
against
Feed
Rate
Figure
of MRR
against against
Workpiece
Figure 6: 6: Graph
Graph
of MRR
Figure
7: 10:
Graph
against
Workpiece
Figure
Graph
of MRR
against
Feed
Rate
Figure 10: Workpiece
Graph of MRR
against
Feed
Rate
Material
Material
Thickness
6
52
VOL
2017
VOL 70
55 APRIL-JUNE
JUNE 2013