A novel in-process monitoring system employing two detectors set above the work at different aiming angles of 5 and 75 degrees was developed to detect whether or not the CO2 laser welding is of full penetration through the back surface of the steel sheets. The acquired signal involved AC components with frequencies up to approximately 10kHz of the emission of the laser-induced plasma in the plume and in the keyhole. The mean square value of the AC signal obtained by using 75-degree sensor in the full-penetration welding was much larger than that of the partial the full-penetration welding, showing that full penetration welding can be monitored with high accuracy by using 75-degree sensor.

1.
E.
Beyer
,
P.
Abels
, “
Processing Monitoring in Laser Materials Processing
”,
Laser Advanced Materials Processing
(
1992
), pp
433
438
2.
L.
Li
,
W.N.
Steen
,
K.
Shi
and
D. J.
Brookfield
, “
Sensor Development for In-process Quality Inspection and Optimization of High Speed Laser Can Welding Process
”,
Laser Advanced Materials Processing
(
1992
), pp.
415
420
3.
J.
Hanting
,
D.
Aiqing
, “
Real-Time Measurement Method of Laser Welding Process with Acoustic Signals and Plasma Radiations
”,
Laser Advanced Materials Processing
(
1992
), pp
457
459
4.
I.
Miyamoto
and
K.
Mori
, “
In-Process Monitoring in Laser Welding of Automotive Parts
”,
Laser Materials Processing
Vol.
77
, ICALEO’93 (
1993
), pp.
413
424
5.
T.
Maiwa
,
K.
Mori
and
I.
Miyamoto
, “
Properties of Keyhole Plasma In CO2 Laser Welding
”,
Laser Materials Processing
Vol.
79
, ICALEO’95 (
1995
)
6.
E.
Beyer
,
K.
Behler
and
G.
Herziger
, “
Plasma Absorption Effects in Welding with CO2Lasers
”,
High Power CO2 Laser System & Applications ECO1, SPIE
Vol.
1020
(
1988
), pp.
84
95
7.
I.
Miyamoto
and
H.
Maruo
, “
Spacial Temporal Characteristics of Laser-Induced Plasma in CO2 Laser Welding
”,
Proc.LAMP
92
(
1992
), pp.
311
316
This content is only available via PDF.
You do not currently have access to this content.