Achieving high strength multi-material joints
As part of the need to minimise vehicle weight, EV Body in White structures can consist of a combination of different materials, such as steel, aluminium and carbon fibre, that require fast and effective joining, as well as stacks of similar materials.
March 21, 2024
In addition, EV battery assembly also presents the need to join dissimilar materials and achieve high strength multi-material joints without generating heat or waste material. Once the battery cells are joined together, they need to be reinforced with lateral braces, to protect the cell stacks from impact forces in 5he event of a vehicle collision.
Typical joining techniques, such as drilling or resistant spot welding (RSW), are not suitable for EV battery assembly because the heat generated and resulting metal fragments or welding splatter can harm and compromise the safety of the sensitive battery cells.
Atlas Copco’s innovative solution to this challenge is self-pierce riveting, a cold joining technique which allows multiple layers of different materials to be joined to create a high strength joint that is visibly checkable. As a clean and purely mechanical process, self-pierce riveting does not require any preparation or rework of the surfaces to be joined.
Self-pierce riveting does not generate heat, surplus material or any hazardous vapours, making the joining method ideal for battery module assembly. Compatible with adhesives and lubricants, the process can also be used with coated or painted surfaces. Another key advantage of self-pierce riveting is that the process was designed to be applicable for joining multiple layers of different materials, such as aluminium and steel.
Equally, Atlas Copco has ensured the optimum balance between the weight and strength of rivets, to achieve the highest levels of joint integrity and durability, whilst also considering the importance of weight reduction in EV manufacture.
As with all Atlas Copco assembly solutions, self-pierce riveting provides error-proofing and traceability as standard, giving peace of mind for manufacturers. As a reliable, time-saving solution for challenges involving hard joints, self-pierce riveting delivers precise, repeatable accuracy, that’s highly reliable with a fast cycle time.
With innovative joining technologies and a range of solutions that can be applied throughout the entire EV assembly process, Atlas Copco is your strategic partner for electromobility. Take a look at our video to see how we can help with your electromobility needs.