'
Research
on
sinusoid modulated pulse
MIG
welding
methodology
75
•
Research on sinusoid modulàted pulse MIG welding methodology
•
Wei
Zhonghua , Chen
Xi
α
ofeng
and
Xue
Ji
田归
ng
魏仲华,陈小峰,薛家祥**
Abstract
This article proposed a new methodology and the principle
of
sinusoid moditlated pulse
MIG
welding ,
and
systematically established the universal mathematical model
of
co
叩
utation
of
the parameters
of
the sinusoid
modul
α
tion
pulse ,
。
chieving
th
α
t
the welding energy
i
叩
ut
can
be
电庐
ctively
controlled
α
nd
precisely regulated , the tra
n.s
ition
of
pulse change
is
smooth
a
阳
1
the welding process
is
st
α
ble
α
nd
reliable. With the
ch
α
racteristics
of
sinusoidal
wm
价
rm
,
such
ω
infinite
derivative
continuity
, eternal
periodicity
αnd
limited control parameters , this article established the theoretical
foun
由旧
n
for choiceness ,
unifìc
α
tion
and optimization
of
the
p
α
ra
阳
ters
during the new sinusoid modulated pulse MIG
weldi
昭
.
Bead-on-plate overlay
welding
is
carried out on the
pure
α
luminum
sheet test sample for the test. The result indicated that during the welding process ,
the real-time current
1
削价
rm
is
stα
ble
and
clear; both the corresponding
volt
α
ge
α
nd
the
i
n.s
t
α
nt
welding energy
wav
价
rm
α
陀
very stable; the repeatability
of
the U-I graph plotted
is
high;
its
family
of
lines
is
clear , neat ,
and
its distribution
is
concentrated showing that the welding process
is
stable
and
the
ne
α
t
and
high quality ripple weld seäm
may
be
produced.
Key words sinusoid modulation , sinusoid modulated pulse
MIG
welding ,
parameter turpng
•
o
Introduction
Along with
development
of
modem
science
technology ,
light weight alloy material
has
been
widely
used
in
modem
indust
巧,
such
as
aluminum
magnesium
alloy
materia
l.
Due
to good
heat
conducting
property,
greater
expansion
ratio
under
high
temperature
and
greater
shrinking
rate
when
cooling
,
it
is
considerably
difficult to
be
welded.
Especially
for the welding
of
aluminum
magnesium
alloy thin
plate
ma-
terial
etc.
, how to avoid
the
problems
of
weld
penetration
and
large welding deformation ,
and
how to
achieve
the
sta-
ble
welding for
aluminum
magnesium alloy material j re-
mains
a difficult
problem
puzzling
the
Chinese
and
intema-
tional
academic
circle[ 1 J.
The
digitized welding power
sup-
ply
based
on
DSP is a major
resèarch
hot spot
in
modem
welding power
supply
area
,
as
it
is
characterized
by strong
data-handling
capacity
, good
real-time
control performance
and
realization of
intellectualized
adjustment
etc.
[2J
•
With
the
aid
of
the
powerful functions
of
DSP,
Chi-
nese
and
intemational
researchers
have
studied
a variety
of
weldingmethodologies
for
the
welding
of
aluminum
alloy
material
[3 J. Among
other
things ,
double
pulse
MIG
welding
is a
practical
technology
designed
for
aluminum
alloy weld-
ing
based
on
conventional
,画
pulse
M~G
welding
teqhnology.
While
the
neat
weld
seam
appearance
may
be
obtained
,
the
double
pulse
MIG
Wedlil
出
ng
飞
an
also
achieve
hi
咆
ghe
曰
r
welding
. efficiency
,
reduce
the
blowhole formation
rate
and
diminish
the
weld
seam
crystal
grain
[
4
J.
The
double
pulse
welding
started
to
be
applied
in
Japan
in
the
end
of
20 century[5
J
•
It
is
so far
one
of
the
best
solution for
aluminum
alloy weld-
ing
,
but
it does not have universal
and
unified regularity
and
theoretical systematicness.
Based
on
sinusoid
theory, this
article
established
the
principle
and
methodology of sinusoid
modulated
pulse
MIG
welding
(hereinafter
referred to
as
"SP-
MIG"
).
By
estab-
lishing
universal
.ll1
athematical
model systematically, the
welding
energy
input
can
be
effectively controlled a
Ìl
d
accu-
rately
regulated
,
the
transition of
pulse
change
becomes
smooth
and
the
welding process becomes
stable
and
relia-
* National Natural Science Foundation Project
(50875088);
Guangdong Province Science and
Technology
Research Project
(20