Controlling flow to optimize arc welding process

weld 67640 640 compressorAlthough I, myself, have never welded (I’d definitely hurt myself), I have spent some time watching my boyfriend practice welding by attaching random pieces of metal together in his garage. Not my idea of a good time, but he couldn’t stand sitting in front of a computer all day. So, I guess to each their own.

My boyfriend isn’t a professional welder, rather a do-it-all tinkerer and mechanic, so optimization isn’t really what he’s after when he’s welding; he just wants a perfect weld. But for those in some areas of manufacturing, welding is an essential process, which must be optimized like all others.

Recently published research lead by Professor Hongbiao Dong from the University of Leicester’s Department of Engineering found that arc welding can be optimized by controlling the flow of the melt pool, while also adjusting the active elements on the surface.

The research was conducted in collaboration with: Delft University of Technology, Diamond Light Source, University College Dublin and TATA Steel Research UK, according to an article on the University of Leicester’s News site.

“Understanding what happens to the liquid in melt pools during welding and metal-based additive manufacturing remains a challenge. The findings will help us design and optimize the welding and additive manufacturing processes to make components with improved properties at a reduced cost,” Dong said in the article. “Welding is the most economical and effective way to join metals permanently, and is a vital component of our manufacturing economy.”

The research

In order to explore the flow behavior in arc welding, the research was focused on melt pools created during the process, the article reports.

“To do this, the team inserted small tungsten and tantalum particles into the melt pool. Due to their high melting points, the particles remained solid in the melt pool long enough for them to be tracked using intense beams of X-rays,” the article states.

The researchers used the synchrotron particle accelerator at Diamond Light Source to produce the X-rays, and selected Beamline I12 for its high-energy, high-speed imaging.

“Using Beamline I12, the researchers were able to create high-speed movies showing how surface tension affects the shape of the welding melt pool and its associated speed and patterns of flow,” the article reports. “The results showed, for the first time, that the melt flow behavior is similar to that previously only seen via computer simulations.”

The researchers believe that this research will help with future designing and optimization of arc welding and manufacturing processes. Nevertheless, this is an interesting example of a unique application of flow measurement.