Glossy aluminum surfaces are among the most demanding areas of application in automated welding technology. High reflections, intense process light and constantly changing conditions during MIG welding significantly affect the detection of seam geometry. At the same time, the requirements for precision, repeatability and process stability are increasing.
The central question from practice is therefore: How can stable and reliable seam tracking be ensured on shiny aluminum?
Aluminum was used as a reference material to evaluate typical application scenarios – with practical seam shapes such as:
These geometries place different demands on the profile display. While the gap must be precisely detected in the butt joint, the overlap joint requires clear edge detection. In the case of the T-joint, it is crucial to clearly distinguish vertical and horizontal structures from each other.
The evaluation was carried out both during the active MIG welding process and on the basis of the profile display and seam tracking in the uniVision software.
Experience from applications and accompanying tests with various MLZL displacement sensors shows that wavelength in particular plays an important role. Blue laser lines on shiny aluminum provided more stable and high-contrast profiles than red variants. Reflections had less of an effect on the measurement results, and edges could be displayed more clearly.
The exposure time also has a significant influence on process stability. Shorter exposure times reduced the interference caused by the welding light and ensured more uniform profiles – especially during the active welding process.
In addition, it was shown that even variants with laser class 2 can produce stable profiles. For many applications, therefore, no higher laser class is required, provided that the parameterization is chosen appropriately.
However, not every sensor variant is equally suitable for highly reflective materials. Targeted selection is therefore crucial.
With the “Profile Seam Tracking” module in the uniVision software, tracking points could be reliably determined for all seam shapes considered. The standard templates were used; only sensor-specific parameters such as exposure time, signal selection and line rate have been adjusted.
Especially with more complex geometries such as the T-joint, it became clear how important a stable and clear profile representation is for safe seam guidance.
Stable seam tracking in MIG welding of aluminum depends on the interaction of wavelength, parameterization and software. Different seam shapes have different requirements – and this is exactly where an application-oriented selection of the right MLZL variant pays off.
If you want to reliably master reflective surfaces, you should tailor the sensor and settings to the task at hand – for greater process reliability and consistently high seam quality.
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