Metrological investigation of arc welding

Andreas Richter, M.Sc.

Summary

In Wire Arc Additive Manufacturing (WAAM), the quality of the material application depends on process parameters such as the melting bath temperature. Many properties can be adjusted by measuring the molten bath temperature with a temporal and spatial resolution. For a real-time process measurement, the temperature of the molten metal must be measured through the arc. The measuring system should enable the temperature to be measured without contact and with high spatial resolution.

For this purpose, a quotient pyrometer was set up at IEI that is insensitive to the radiation emitted by the arc. The actual measurement of the temperature is done by image processing in MATLAB.

In addition, there are examinations using Laser Doppler Vibrometry to record further process parameters.

The project is carried out in cooperation with ISAF.

Current subprojects

• For direct control, the result should be sensibly reduced to a few scalar quantities, such as the total area or the width.
• Full or partial automation of pyrometer settings to simplify set-up on the welding robot.
• Definition of influencing variables of the welding process on the plasma of the arc.
• Optimization of the pyrometer to cover a wider temperature range. This should also allow the interlayer temperature to be measured.

A. Richter, M. Scheck, C. Bohn und C. Rembe:
Erfassung der Schmelzbadfläche mit Korrektur der Perspektive zur Prozessregelung eines Wire and Arc Additive Manufacturing
^{In: tm - Technisches Messen. 2022 - to be published . DOI: 10.1515/teme-2022-0009.}

A. Richter, M. Scheck, T. Gehling, C. Bohn, V. Wesling und C. Rembe:
Erfassung geometrischer Daten des Schmelzbades zur Regelung eines WAAM-Prozesses
^{In: tm - Technisches Messen. Vol. 88, Issue s1, pp. 95-100, Aug. 2021. DOI: 10.1515/teme-2021-0072 .}

A. Richter, T. Gehling, K. Treutler, V. Wesling, and C. Rembe:
Real-time measurement of temperature and volume of the weld pool in wire-arc additive manufacturing
^{In: Measurement: Sensors 17,2021,100060,ISSN 2665-9174. DOI: 10.1016/j.measen.2021.100060 .}

A. Richter, C. Rembe, T. Gehling, K. Treutler and V. Wesling:
Real-time temperature measurement at wire arc additive welding
_{In: tm - Technisches Messen. Vol. 86, Issue s1, pp. 112-116, Aug. 2019.}
^{DOI: 10.1515/teme-2019-0057 .}