1998 年 16 巻 2 号 p. 189-198
We are researching the plasma behavior in laser welding and the applicability to monitoring. We reported the direct observation method for laser welding and clarifying the formation of shield gas plasma by detective signals in the first paper. And we reported the appearances of the detected signals with laser welding conditions in the second paper. This paper describes the correspondence of the directive signals to the bead on plate with artificial defects.
The main results are as follows;
⋅The signals of spectrum emission and plasma potential changed their wave form at touched together stainless plates.
⋅The combination of the signals from the spectrum emission and plasma potential gave more definite information on the welding abnormality, such as fluctuation of penetration depth, etc.
⋅Three detective signals were changed at the vertical hole and their wave forms varied before the hole position.
⋅The molten flow was observed by longitudinal cross section in weld test which Ni powder is packed in side holes.
This work was performed under the management of ALERI (Applied Laser Engineering Research Institute) as a part of "the Leasing Basic Research Practical Use of Research Facility Centers" supported by NEDO (New Energy and Industrial Technology Development Organization).