Jan 17 2019
A new study, led by the University of Leicester, will improve the welding and additive manufacturing process.
Additive manufacturing and arc welding are of great significance for producing large metal components quite rapidly and inexpensively.
A new study led by Professor Hongbiao Dong from the University of Leicester’s Department of Engineering has demonstrated the way this process can be optimized to enhance cost-effectiveness and efficiency.
The collaborative research, which included the University of Leicester, Delft University of Technology, Diamond Light Source, University College Dublin, and TATA Steel Research UK, was recently reported in Nature Communications.
It looks into the internal flow behavior during the additive manufacturing of metals and arc welding, which are the most extensively used welding processes in modern manufacturing.
The research concentrated on investigating the melt pools that are formed at the time of the welding process.
In order to perform this, the researchers introduced small tungsten and tantalum particles into the melt pool. Their high melting points enabled the particles to remain solid in the melt pool long enough for them to be traced with the help of powerful X-ray beams.
The synchrotron particle accelerator at Diamond Light Source, which is the UK’s National facility for synchrotron light, was used to produce the X-rays. Owing to its high-speed imaging capability at thousands of frames per second and specialized high energy, Beamline I12 was chosen for this research.
With the help of Beamline I12, the scientists could create high-speed movies displaying the impact of surface tension on the shape of the welding melt pool and its related speed and patterns of flow. The results demonstrated, for the first time, that the melt flow behavior is analogous to that which was earlier viewed only through computer simulations.
The results showed that it is possible to optimize the arc welding process by controlling the flow of the melt pool and by varying the associated active elements on the surface.
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. Welding is the most economical and effective way to join metals permanently, and is a vital component of our manufacturing economy.
Hongbiao Dong, Professor, Department of Engineering, University of Leicester
The I12 team was closely involved in the experiment. The beamline was designed with these challenging in-situ experiments in mind and I am very happy that we have helped advance understanding of additive manufacturing and welding, given their technological importance.
Dr Thomas Connolley, Principal Beamline Scientist for I12, Diamond Light Source
More than 50% of global domestic and engineering products is estimated to have welded joints. The welding industry in Europe has conventionally supported a varied range of companies across the pipeline, shipbuilding, aerospace, automotive, defense, and construction sectors. In 2017, income from welding equipment and consumable markets reached €3.5 billion in Europe.
The results will assist with the future designing and optimization of the welding and additive manufacturing process and will have a significant and extensive impact.