Abstract

In-process monitoring and feedback control are fundamental actions for stable and good quality laser welding process. In particular, penetration depth is one of the most critical features to be monitored. In this research, overlap welding of stainless steel is investigated to stably reproduce a fixed penetration depth using both CO 2 and Nd:YAG lasers. Plasma electron temperatures of Fe(I) and Cr(I) are evaluated as in process monitoring using the measurement of intensities of emission lines with fast spectrometers. The sensor system is calibrated using a quantitative relationship between electron temperature and penetration depth in different welding conditions. Finally closed loop control of the weld penetration depth is implemented by acquiring the electron temperature value and by adjusting the laser power to maintain a pre-set penetration depth. A PI controller is successfully used to stabilize the electron temperature around the set point corresponding to the right penetration depth starting from a wrong value of any initial laser power different than the set point. Optical inspection of the weld surface and macroscopic analyses of cross sections verify the results obtained with the proposed closed-loop system based on a spectroscopic controller and confirms the reliability of our system.

Autore Pugliese

• Sibillano Teresa , Ancona Antonio

Tutti gli autori

• Sibillano T.; Ancona A.; Rizzi D.; Mezzapesa F.; Konuk A.R.; Aarts R.; Huis In 't Veld B.; Lugarà P.M.

Titolo volume/Rivista

Non Disponibile

Anno di pubblicazione

2012

ISSN

Non Disponibile

ISBN

9780819488824

Numero di citazioni Wos

Nessuna citazione

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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