Using 3D multi-scale multi-physics mathematical models, UBC Okanagan researchers have developed a process to predict when cracking will occur in fusion welding.
Fusing welding is a generic term for welding processes that rely on melting to join metals with similar compositions.
This type of welding is used in a wide range of industries including oil and gas, automotive, aerospace and medical devices.
A common defect in fusion welding is hot cracking or solidification cracking. This defect forms during welding or immediately after the weld has set.
The researchers at UBC Okanagan used a numerical model consisting of four separate components to predict the cracking.
Graduate student Hamid Zareie Rajani says several factors cause hot cracks. “We know that welding settings, and impurities in the metals are often the cause but we were looking for a more accurate way to predict when and where the cracking would occur.”
Rajani worked with Andre Phillion, an associate member of the School of Engneering at UBC Okanagan and an associate professor at McMaster University, to build a crack prediction model that took into account how metal solidified during welding, the impact of equipment settings, how the melted metal flowed, and the way in which the work pieces were clamped.
“By combining all of these effects, and incorporating realistic semisolid geometry, we gain greater insight into where cracks may start in any given fusion weld” says Phillion.
According to Phillion and Rajani, this new prediction model has helped narrow the focus of why hot cracking occurs and may enable the welding industry to further reduce hot cracking in the future.
The research was published in the journal Materials and Design and supported by the American Welding Society and the Natural Sciences and Engineering Research Council of Canada.