BY LINCOLN BRUNNER
New laser weld monitoring systems help users
diagnose problems immediately
For job shops and manufacturers that rely on laser welding to provide
the finish and precision welds other welding methods can’t, one problem
has always been inspection.
While a welder can visually monitor a GTAW or GMAW weld while
laying down the bead, the automatic nature of laser welding precludes
that. Traditionally that’s meant that a laser weld can only be tested by
pulling it out of its native state [ex-situ], tearing it apart and looking at it.
However, with the latest weld monitoring systems from the likes
of Laser Depth Dynamics and Precitec, users can reap a wealth of
information about their welds as they’re happening.
Laser Depth Dynamics’ inline coherent imaging (ICI) system
connects to a laser weld head assembly through a camera port. It then
couples a measurement beam with a unique wavelength with the laser
beam. The measurement beam is reflected from the surface of the
in Real Time
Laser Depth Dynamics' inline coherent imaging (ICI) system connects to a laser
weld head assembly through a camera port. It can track joints, follow height
and do post-weld inspection to measure under;lled areas and surface pores.
workpiece back to the measuring instrument,
which then determines the depth of weld
penetration. ICI, with its new 3D module,
now can track joints, follow height and do
post-weld inspection to measure underfilled
areas and surface pores in one glance. This
in turn can generate 3D surface images of
parts that can be used for future part setup
and robot teaching.
Measuring actual weld depth while the
weld is being made supplants the need for
after-the-fact destructive testing because ICI
can look into the keyhole created by the laser
beam and measure its penetration hundreds
of thousands of times per second. Then,
when something goes wrong, a user knows
how to address the problem at the source.
“Previously the only option for direct weld
depth measurement was ex-situ destructive
testing,” says Chris Galbraith, applications
specialist with Laser Depth Dynamics,
Kingston, ON. “Our customers have a
complete record of each weld they produce
as soon as its finished. Instead of asking
what percentage of their parts likely contain
defects, our customers can ask exactly how
many are defective, exactly when they were
produced and even what went wrong.”
Just as important as the data that comes
out during the weld is the setup that allows
those welds to be done in the first place.
Laser welding, because it’s done by machine,
Laser Depth Dynamic's weld monitoring software
provides real time direct penetration monitoring.
IMAGE COURTESY OF LASER MECHANISMS.