Interesting (to me) article in latest issue of Practical Welding Today on "keyhole GTAW". It is strictly for large scale, automated welding so it likely won't come to any artist blacksmith shops any time soon. However, we don't see (or at least I don't) big changes on the welding technology front very often, so you may be interested in reading for your information. The link to the K-TIG website is interesting also with quite a bit of information.
7 - Article - Keyhole GTAW
This article introduces a relatively new technology marketed by a commercial company, (http://www.k-tig.com/), owner of patents on the system, that cannot probably be purchased from alternative suppliers.
No recommendations or endorsement are intended by this publication. The reason is to provide information on a new or less known process which might show advantages in specific applications.
Interested readers should check on their own if it might offer them economic benefits.
A variant of the well known and trusted GTAW (Tig) process was developed in Australia at the end of the 1990s by the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia's national science agency, through its Manufacturing and Infrastructure Technology (CMIT).
It is offered as a complete system including a special torch, constant current power supply with output of 300-700A (and up to 1000A at 100% duty cycle) and integrated controller.
The main advantage is high productivity for:
- Suitable applications presenting good joint fit-up, typically pipes
- Materials: Stainless, Titanium, Zirconium, 3 mm thick up to 20 mm
- Single pass process with simple square butt joint
- Full penetration with no filler metal
- Automated production lines welding in flat or horizontal position
As this k-tig welding technology is based on keyhole formation in the joint, it is readily comparable to plasma welding equipment, and to friction stir welding, by taking into account all the elements of any specific production line.