Dynamic electrode displacement and force were characterized during resistance spot welding of aluminum alloy 5182 sheets using a medium-frequency direct-current welder. It was found that both electrode displacement and force increased rapidly at the beginning of the welding stage and then at a reducing rate. Rates of increase in electrode displacement and force were both proportional to welding current. And both electrode displacement and force experienced a sudden drop when weld metal expulsion occurred. However, the rate of increase in electrode displacement did not reach zero during welding even for joints with sufficient nugget diameter, while electrode force peaked when a large nugget diameter was produced. Possible strategies for process monitoring and control were also discussed.

Issue Section:
Technical Papers
Keywords:
aluminium alloys, welding electrodes, welding, process monitoring, spot welding
Topics:
Displacement, Electrodes, Welding, Aluminum alloys
1.
RWMA, Resistance Welding Manual (Fourth Edition), 1989, Resistance Welder Manufacturers Association, Philadelphia, PA.
2.
Beatson, E.V., 1977, “An Introduction to Quality Control Systems in Resistance Welding,” Resistance Welding Control and Monitoring, K.I. Johnson, ed., The Welding Institute, Abington Hall, Abington, Cambrdge, UK, pp. 2–7.
3.
Messler
,
R.W.
, and
Jou
,
M.
,
1996
, “
Review of Control Systems for Resistance Spot Welding: Past and Current Practices
,”
Sci. Technol. Weld. Joining
,
1
(
1
), pp.
1
–
9
.
4.
Janota, M., 1974, “The Relationship Between Thermal Expansion and the Growth of a Resistance Spot Weld,” The Third International Conference on Advances in Welding Processes, The Welding Institute, Paper 40, Harrogate, 7–9 May, pp. 21–26.
5.
Chien
,
C.-S.
, and
Kannatey-Asibu
, Jr.,
E.
,
2002
, “
Investigation of Monitoring Systems for Resistance Spot Welding
,”
Weld. J. (Miami, FL, U. S.)
,
81
(
9
), pp.
195-s–199-s
195-s–199-s
.
6.
Tang
,
H.
,
Hou
,
W.
,
Hu
,
S.J.
, and
Zhang
,
H.
,
2000
, “
Force Characteristics of Resistance Spot Welding of Steels
,”
Weld. J. (Miami, FL, U. S.)
,
79
(
7
), pp
175-s–183-s
175-s–183-s
.
7.
Cho
,
H.S.
, and
Chun
,
D.W.
,
1985
, “
A Microprocessor-based Electrode Movement Controller for Spot Weld Quality Assurance
,”
IEEE Trans. Ind. Electron.
,
IE-32
(
3
), pp.
234
–
238
.
8.
Waller
,
D.N.
, and
Knowlson
,
P.M.
,
1965
, “
Electrode Separation Applied to Quality Control in Resistance Welding
,”
Weld. J. (Miami, FL, U. S.)
,
44
(
12
), pp.
168-s–174-s
168-s–174-s
.
9.
Haefner
,
K.
,
Carey
,
B.
,
Bernstein
,
B.
,
Overton
,
K.
, and
Andrea
,
M.D.
,
1991
, “
Real Time Adaptive Spot Welding Control
,”
ASME J. Dyn. Syst., Meas., Control
,
113
,
March
, pp.
104
–
112
.
10.
Fujimoto
,
K.
,
Nakata
,
S.
, and
Nishikawa
,
M.
,
1997
, “
Design and Construction of a Loading System for Resistance Welding and Its Dynamic Properties: Optimization of the Loading System in High Current Density Spot Welding With a Short Energizing Time (1st Report)
,”
Welding International
,
11
(
5
), pp.
371
–
377
.
11.
Irving
,
B.
,
1995
, “
Building Tomorrow’s Automobiles
,”
Weld. J. (Miami, FL, U. S.)
,
74
(
8
), pp.
29
–
34
.
12.
Rivett
,
R.M.
, and
Westgate
,
S.A.
,
1980
, “
Resistance Welding of Aluminum Alloys in Mass Production
,”
Met. Constr.
,
12
(
10
), pp.
510
–
517
.
13.
Thornton
,
P.H.
,
Krause
,
A.R.
, and
Davies
,
R.G.
,
1996
, “
The Aluminum Spot Weld
,”
Weld. J. (Miami, FL, U. S.)
,
75
(
3
), pp.
101-s–108-s
101-s–108-s
.
14.
Fukumoto
,
S.
,
Lum
,
I.
,
Biro
,
E.
,
Boomer
,
D.R.
, and
Zhou
,
Y.
2003
, “
Effects of Electrode Degradation on Electrode Life in Resistance Spot Welding of Aluminum Alloy 5182
,”
Weld. J. (Miami, FL, U. S.)
,
82
(
11
), November, pp.
307-s–312-s
307-s–312-s
.
15.
Hao
,
M.
,
Osman
,
K.A.
,
Boome
,
D.R.
, and
Newton
,
C.J.
,
1996
, “
Developments in Characterization of Resistance Spot Welding of Aluminum
,”
Weld. J. (Miami, FL, U. S.)
,
75
(
1
), pp.
1-s–8-s
1-s–8-s
.
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