Title
Closed loop control of laser welding using an optical spectroscopic sensor for Nd:YAG and CO2 lasers
Author
Konuk, A.R.
Aarts, R.G.K.M.
Huis in 't Veld, A.J.
Sibillano, T.
Rizzi, D.
Ancona, A.
Publication year
2011
Abstract
Recent developments in laser joining show the applicability of spectral analysis of the plasma plume emission to monitor and control the quality of weld. The analysis of the complete spectra makes it possible to measure specific emission lines which reveal information about the welding process. The subsequent estimation of the electron temperature can be correlated with the quality of the corresponding weld seam. A typical quality parameter, for laser welds of stainless steel, is the achieved penetration depth of the weld. Furthermore adequate gas shielding of the welds has to be provided to avoid seam oxidation. In this paper monitoring and real-time control of the penetration depth during laser welding is demonstrated. Optical emissions in the range of 400nm and 560nm are collected by a fast spectrometer. The sensor data are used to determinethe weld quality of overlap welds in AISI 304 stainless steel sheets performed both with CW Nd:YAG and CO2 lasers. A PI-controller adjusts the laser power aiming at a constant penetration. Optical inspection of the weld surface and microscopic analysis of weld cross sections were used to verify the results obtained with the proposed closed-loop system of spectroscopic sensor and controller.
Subject
Mechatronics, Mechanics & Materials
TFT - Thin Film Technology
TS - Technical Sciences
Physics
Industrial Innovation
Laser welding
Nd:YAG laser
Plasma spectroscopy
Melt pool control
Electron temperature
To reference this document use:
http://resolver.tudelft.nl/uuid:d9781534-1fd7-441a-b33f-661f460c5dd0
TNO identifier
463871
ISBN
9780912035611
Source
Proceedings of the ICALEO 2011, Orland, Fl, USA, October 23-27, 2011, 85-94
Article number
203
Document type
conference paper