African Fusion July 2023

Cosmo Group: hand held laser welding

Cosmo Group launches 3-in-I hand-held laser

Cosmo Group is introducing cutting-edge new hand-held laser technology into South Africa that offers laser weld ing, cutting and cleaning capabilities from a modern and economical fibre-laser power source. African Fusion talks to Pieter Pistorius of the University of Pretoria about his interest in the system and to Petrus Pretorius of Cosmo Group about its core features and uses.

“ O ur final year metallurgical engineering students at the University of Pretoria (UP) are required to do a classical practical at the end of their degrees, and every year we need to find novel welding-related research ideas. We typically use traditional processes to set up welding experiments, collect the data and then analyse the prop erties and metallurgy of the finished weld. “This really began when we invested in a Lincoln Electric S350 Power Wave weld ing power supply for our SAIW Centre for Welding Engineering, which we purchased from Cosmo Industrial in Silverton a few years ago. We have since started attract ing post-graduate students to do research in the welding field and produced several research papers,” Pieter Pistorius, tells Af rican Fusion . Cosmo, he adds, because it is both easily accessible and offers excellent support on the welding process side, has now become the UP Welding Centre’s go-to supplier of welding consumables and technical sup

port. “We are not welders, so the Cosmo team has become very important to us. They know welding and we can have open discussions with them. When we show them a procedure, they will often ask why we want to do it like that? Then they simplify the welding to enable us to get far more practical and realistic results,” Pistorius says. “We are currently involved in research at all levels into the solidification structure of thin ferritic stainless steel materials, using gas-tungsten (GTAW), gas metal (GMAW) and metal-cored (MCAW) arc welding,” he continues, adding that these steels are typically used for exhaust systems that get very hot. “We try to mimic the welding of exhaust-pipe tubing, for example, with a view to getting a finer grain structure into the weld metal that will be less susceptible to cracking,” Pistorius explains. When Pistorius heard that Cosmo had set up a demonstration unit of a new hand held laser welding system, he scheduled a visit to incorporate the process into the

Cosmo Group is introducing cutting-edge hand-held laser technology into South Africa that offers laser welding, cutting and cleaning capabilities from a modern and economical fibre-laser power source. university’s research programme. “Petrus Pretorius did the welding for us in the demonstration centre at Cosmo. We see this process as an exciting addition to our research programme, as an alternative to GTA welding, for example. While the energy concentration of the beam is high, laser welding is known to offer reduced heat input compared with all traditional processes, which reduces distortion. For our research though, the lower heat input results in less grain growth and, potentially, finer grains with a less columnar and a more equiaxed structure in the weld metal. “For the initial undergraduate project on this machine, the hand-held laser was used without (autogenous) and with filler metal using the machine’s built-in wire feeder, which seemed better. We haven’t yet got any definitive results, though, but we are definitely excited to have a new welding process to explore,” says the head of the SAIW Centre for Welding Engineering at the University of Pretoria. Revolutionary hand-held solutions Describing some of the revolutionary features of the hand-held laser welding systems, Petrus Pretorius starts with safety. “People need to be very careful when using any welding process, and hand-held lasers are no exception. Proper protective equip ment is always necessary and the system does come with purpose designed laser goggles for eye protection,” Pretorius notes. To avoid any possibility of the laser beam being accidently aimed at a person nearby, Cosmo’s hand-held lasers come

The University of Pretoria’s SAIW Centre for Welding Engineering is currently being used for research into the solidification structure of thin ferritic stainless-steel materials.

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July 2023

AFRICAN FUSION