Joining through Electromagnetic Forming

Electromagnetic Crimping Connections

Electromagnetic crimping connections are an excellent method for joining tubular metallic components with various metallic or non-metallic connectors in just a few seconds, with low energy and tooling requirements. The process does not require additional materials, and the connections can be handled and further processed immediately after joining, making it a safe and efficient option. Electromagnetic crimping provides a advantageous alternative to energy-intensive thermal shrink-fitting, other forming-based joining methods such as time-consuming tube rolling or internal high-pressure forming, and adhesive bonding with its complex surface pretreatments and long curing times. Electromagnetic crimp connections are typically not non-destructively releasable but allow for material-specific separation of the joined materials during recycling.

Force-Fit Joining

• Requires only minimal degrees of deformation, making it suitable for joining materials with low ductility.
• The joint geometry is typically simple, eliminating the need for complex preparation steps for the semi-finished products.

Form-Fit Joining

• Load transfer is achieved through the formation of undercuts on secondary forming elements such as grooves or beads.
• This requires locally higher deformations but offers significant advantages, especially for lightweight applications, as the joint and overlap of the joining partners can be designed to be relatively short, saving material and weight.

Magnetic Pulse Welding

Magnetic pulse welding (MPW) enables the joining of tube-, sheet-, or shell-shaped components made of electrically conductive materials, such as aluminum or copper alloys, with various metallic materials. This process can also create mixed joints of material combinations that are considered difficult or impossible to weld using conventional (thermal) methods. The key principle is that the joint is formed through high-speed collision of the joining partners as a result of acceleration by Lorentz forces, without external heat input and without macroscopic melting. This avoids temperature-induced limitations of thermal welding processes, such as the formation of critical oxide or intermetallic phases, thermal softening of the material, or heat distortion. The process does not require any auxiliary or additional materials, and the joints can be handled and further processed immediately after welding.

Research at Fraunhofer IWU has shown that magnetically pulse-welded joints exhibit excellent mechanical strength and electrical and thermal conductivity. The process requires relatively little energy, is environmentally friendly and user-friendly, and is highly automatable and reproducible. Magnetic pulse welding has particularly high potential for the production of:

• Aluminum Mixed Joints for Lightweight Applications:
  • Ideal for creating strong and lightweight structures in automotive, aerospace, and other industries.
• Electrically Conductive Joints for Electrical and Power Engineering:
  • Suitable for applications requiring reliable electrical conductivity, such as battery systems or power electronics.
• Thermally Conductive Joints for Cooling or Heating Systems:
  • Essential for components in HVAC (heating, ventilation, and air conditioning) systems, heat exchangers, or other thermal management applications.