Resistance & Solid-State Processes

EWI combines deep expertise in resistance and solid-state welding technologies with materials science and controls engineering knowledge to support manufacturers in optimizing process parameters, embedding quality monitoring technology in existing control systems, and integrating state-of-the-art performance prediction methods.

EWI’s Resistance and Solid-State Welding team develops technologies that employ electrical current flow as the primary means of heating pieces for joining, or achieve joining through solid-state (rather than fusion or brazing) mechanisms.

Dynamics of Resistance Spot Welding

Resistance welding technologies typically use Joule, or resistance heating, to ensure a successful weld. Solid-state processes use deformation and diffusion to join materials without molten and re-solidified material in the final bond area.

Our team works to develop and advance state-of-the art resistance technologies while providing high-level solutions for customers in the automotive, aerospace, advanced energy, consumer and industrial products, and oil & gas industries.

The EWI team has more than 165 years of combined experience in solid-state and resistance methods, metallurgical assessment, design-of-experiment methods, instrumentation and control, mechanical fastening, and modeling and simulation for the manufacturing industry. Based on this expertise, EWI has been able to introduce many new innovations in the field, such as conductive heat welding, resistance hole repair, and resistance pipe cladding.

Technical Expertise

Solid-state methods

  • Hot upset
  • Cold pressure
  • Solid projection
  • Magnetic pulse
  • Diffusion
  • Stud
  • Flash butt
  • Resistance butt
  • Dissimilar materials

Resistance methods

  • Spot
  • Conductive heat
  • Embossed
  • Projection
  • Seam
  • Electro-spark deposition
  • Percussive
  • Brazing
  • Indirect resistance heating

Equipment and Lab Resources

  • Resistance Spot Welding: five pedestal spot welding frames, two MFDC servo-guns, process instrumentation
  • Projection Welding: Current capability less than 1,000 to over 700,000A, force capability less than 400N to over 200kN, three large welding frames, five small welding frames
  • Resistance Seam Welding: five separate seam welding systems, dedicated tooling tables for workpiece manipulation, dedicated tooling for pipe cladding
  • Flash Butt/Upset Butt Welding: Two flash/upset butt welding frames, assurance flash/upset butt welding control, translational capability on the smaller welding frame
  • Power Supplies and Controls: AC transformers ranging from 5kVA to 400kVA, secondary rectified DC systems to 600kV, MFDC transformers up to 1500kVA, MFDC inverters up to 4kA, frequency converter DC system

EWI keeps pace with high-demand market needs while innovating within the field of resistance welding. The ability to create innovative concepts, translate them to candidate applications, and deliver to decision-making points has helped to establish our team as a leader in resistance and solid-state processes.

EWI’s Resistance and Solid Processes team has proven their ability to solve high-impact problems for customers again and again. Below are examples of some significant projects.

  • An automotive Tier 1 parts supplier needed to improve the crash-impact performance of seat structures. During crash testing, critical elements of the assembly were buckling, compromising overall performance and raising significant safety concerns. EWI’s experts provided guidance on localized thermal processing of these critical sheet-metal components, allowing the creation of specific microstructural architectures to enable designed crash modes. This use of tailored microstructures allowed the design of next-generation lightweight structures using a wider range of base materials while meeting crash worthiness requirements.
  • EWI’s modelling and welding experts teamed up to help a customer integrate state-of-the-art prediction methods for assessing vehicle crash performance to reduce required levels of physical testing and enhance product times to market. EWI provided an innovative experiment-based design solution for crash prediction.
  • A Tier 1 automotive supplier that manufactures HVAC components was experiencing a 30% failure rate due to leakage at resistance projection welds. EWI provided welding expertise and helped the customer take advantage of monitoring technology embedded in their existing control system to detect discrepant joints. After demonstrating that the monitoring system could reliably identify defects, EWI worked with the original equipment manufacturer to remove the quarantine label from the supplier.

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