In a significant advancement for the electric vehicle (EV) industry, researchers have introduced a novel approach to mitigate thermal-induced buckling during the laser welding of battery housings. This innovative method, termed “unilateral N-2-1 fixturing,” addresses a critical challenge faced by manufacturers working with high-strength 6xxx aluminum alloys, which are increasingly used for lightweight battery housings.
Anand Mohan, the lead author from the Warwick Manufacturing Group (WMG) at the University of Warwick, explains that the design of battery housings must meet stringent requirements, including collision resistance and impermeability to gases and water. As electric vehicles strive for lighter structures, the use of thin sheets of aluminum has become common, leading to potential issues during welding processes. “Thermal-induced buckling may occur and generate critical dimensional unconformities going beyond design tolerances,” he states, highlighting the urgency for improved fixturing solutions.
The proposed unilateral N-2-1 fixturing method is a step beyond existing techniques. It involves adding unilateral restraints to control the direction of thermal contraction while allowing thermal expansion to occur freely. This targeted approach significantly reduces the risk of deformation during welding. The research employed a three-step methodology: first, a physics-based modeling of parts and fixtures using thermo-mechanical finite element analysis (FEA) simulations; second, the calibration of the welding heat source with metallographic data; and third, validation through optical scanning technology.
The results of this research are compelling. When the unilateral N-2-1 fixturing was utilized, thermal-induced buckling deformation was reduced from 15 mm to approximately 2 mm, demonstrating a marked improvement over traditional methods. This reduction in deformation is crucial for maintaining the structural integrity of battery housings, which is vital for the performance and safety of electric vehicles.
The implications for the energy sector are substantial. As the demand for electric vehicles continues to rise, manufacturers must ensure that battery housings are not only lightweight but also robust and reliable. This new fixturing approach could lead to more efficient production processes, lower costs, and ultimately, better-performing vehicles.
This research has been published in the ‘Journal of Advanced Joining Processes’, underlining its contribution to the field of advanced manufacturing techniques. For more information about the research and its applications, you can visit the Warwick Manufacturing Group.