Are you seeking an automated solution to assess quality, reliability, and safety in your manufacturing operation?
EWI recently worked with materialsIN to develop a real-time quality assurance system for ultrasonically welded, lithium-ion battery tabs. In a new paper, A Fully Automated Quality Assurance Solution for Battery Tab Welds Using Process Monitoring and AI, EWI engineers Alex Kitt and Zach Corey describe how EWI recently combined sensor selection, AI, and intelligent training data generation to create an elegant inspection and verification system.
You are invited to download this paper for FREE by completing the form on this page.
To learn more about quality assurance solutions developed by EWI, contact Alex Kitt at [email protected].
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Integrated computational materials engineering (ICME) uses analytical and numerical tools to create predictive models. Recently, EWI has published a series of papers examining analytical methods that work well in assessing thermal/mechanical responses in specific joining processes.
Some highly complex joining applications, however, require advanced computational tools such as finite element analysis (FEA) to achieve desired accuracy. EWI has successfully used FEA to predict thermal behavior in different joining applications including two specific cases: 1) thermal excursions in battery module electrical interconnects, and 2) residual stress and distortion in arc welding processes.
You can read about this work in Thermal Analysis Using Finite Element Methods, written by EWI Project Engineer Amin Moghaddas. Simply complete the form on this page to download the paper for FREE.
Staying competitive in large-structure production is vital for American industries today. The Accelerating Production of Large Structures and Systems (RAPLSS) survey initiative, sponsored by NIST Manufacturing USA and managed by EWI, aims to streamline this process.
The Need for Large Structure Production 4.0 Technologies
US industries must adopt leading-edge technologies for large structure production 4.0 to stay competitive globally. The RAPLSS roadmap takes a three-fold approach to reach its objectives:
Development of Large Structure 4.0 Technologies: This involves using automation, data analytics, and IoT to optimize large structure production processes.
Next-Generation Manufacturing, Fabrication, & Inspection Processes: Innovations in materials and techniques are crucial for improving production efficiency and reducing costs.
Advanced Training Programs: Preparing the workforce for the future is a priority. The roadmap focuses on creating training programs to equip individuals with skills needed for modern manufacturing.
The RAPLSS initiative aims to identify specific industry gaps and needs to enhance American manufacturing in large structures and systems. By prioritizing innovation, efficiency, and workforce development, it aims to position the U.S. as a leader in this field. However, achieving this vision requires industry-wide participation from experts, manufacturers, and researchers. Please take NIST’s 5-minute survey to share your insights and participate in accelerating production in this critical sector. Questions about this survey? Contact Larry Brown, Senior Project Manager/Technical Advisor, Government Programs at[email protected].
EWI is pleased to welcome Commonwealth Fusion Systems (CFS) to membership. The company designs and builds fusion energy systems to achieve its mission of delivering clean, limitless fusion power to the world.
EWI has recently developed a new technique to obtain improved accuracy in material flow stress for modeling metal forming processes.
The method uses the hydraulic bulge test (HBT) and digital image correlation (DIC) analysis and applies the plastic work equivalency principle to determine an optimal arc length for the for calculation of a biaxial flow curve. It yields a maximum uniform equivalent strain that is twice the maximum uniform strain that could be obtained in the past, thus offering improved accuracy.
EWI associates Amir Asgharzadeh and Laura Zoller have written Advanced DIC Post-processing Technique to Analyze Biaxial Bulge Test to describe this work. You are invited to download this paper FOR FREE by completing the form on this page.
To discuss this technique or other forming tests offered by EWI, contact Laura Zoller at [email protected].
Have you seen the new process known as tele-welding? Have you ever TRIED it? You’ll have your chance when you visit the CWB-EWI booths at FABTECH 2023, September 11-14 in Chicago.
The setup for a tele-welding workstation
Come drive the cutting-edge robotic system that can perform welding, gouging, cutting, and inspection from remote locations. You’ll get the full experience of live video visuals, haptic feedback, and real-time operation as you lay down high-quality gas metal arc welds using EWI’s unique tele-manufacturing technology. The remote execution of your work will take place LIVE in a booth located across the expo hall. EWI associates will be on hand at both booths to guide you through the process and answer your questions.
To watch the control system at work – or operate it yourself – visit FABTECH Exhibit Booth #16033. The remote welding robot will be set up in a separate location several rows away at Booth #37003. We invite you to check out both ends of the operation while you visit the show.
Tele-manufacturing is just one of many innovations that EWI has to share at FABTECH. You can learn about our broad capabilities, services, and innovations when you stop by our exhibit. In addition, EWI associates will be giving ten presentations on recent R&D as part of the AWS Professional Program. For a complete list of speakers, visit ewi.org/ewi-event/fabtech-2023.
Common aerospace materials such as high-nickel alloys (such as René 80) or high-strength aluminum alloys (6000 and 7000 series) are not currently manufactured using additive manufacturing (AM) due to hot cracking. As part of a $5M Department of Energy program, EWI, GE Research, and the University of South Carolina developed a model to predict and avoid hot cracking in René 80. Using additive manufacturing for high performance metal alloys enables design flexibility and the introduction of previously unbuildable parts.
When the measured crack formation for a set of René 80 single-pass walls is plotted against the velocity of the solidification front, a clear activation behavior is observed. This is consistent with the physics-based crack formation criteria and provides a mechanism for predicting and avoiding crack formation.
Our probabilistic crack formation model is an ICME based Process->Thermal->Structure model. The steps in this model is described below:
Process > Thermals: Process parameters and part geometry are used to predict the thermal history experienced by the René 80. This is done using a multi-source Rosenthal model. Rosenthal models are one example of computationally efficient analytic methods EWI often uses for thermal history prediction. In this case, we calibrate the model using in-situ thermal sensing.
Thermal > Structure: A hot cracking criteria is used to relate the predicted thermal histories to crack formation. In this case, we use a simplified version of the physics based RDG crack formation criteria. This model considers the fluid flow between dendrite arms during solidification.
The Process > Thermal > Structure model allows crack formation predictions to be made in seconds and gave consistently good results across multiple builds. Further, the model can be used in a feedback loop to select process parameters, modify design, and modify build strategy to minimize or eliminates cracking.
This specific approach was developed for René 80 but is applicable for other hot-cracking prone alloys.
For a full explanation of the development of this model, you can view our recently published paper in ADDITIVE MANUFACTURING, Physics-based Crack Formation Model for René 80 in laser Blown Direceted Energy Deposition: Theory and Experiment, by filling out the form below:
To discuss this work and how it might be applicable for your application, contact Alex Kitt at [email protected] or Matt Dodds at [email protected].
This work was supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Advanced Manufacturing Office Award Number DE-EE0009118
Integrated computational materials engineering (ICME) can be used effectively to understand thermal excursions and mechanical response in single-shot joining methods such as resistance-spot, flash-butt, friction, hot-gas, and thermite welding.
As part of EWI’s ongoing series of papers examining the uses of ICME as a prediction tool in manufacturing, Senior Technology Leader Jerry Gould has written Analytical Tools for Assessing Thermal/Mechanical Response During Single-shot Welding Processes. This paper examines the unique constructs for this application and how they can be used to address concerns ranging from process deterioration to new manufacturing control strategies.
You are invited to download the paper FOR FREE by completing the form on this page.
Complete this form to download the paper:
To view the paper, please submit the form above.
Interested in learning more about EWI’s work in ICME? Check out these related papers by our authors:
Microjoining encompasses techniques including welding, brazing, soldering, and adhesive bonding. Typically, the technology involves materials with thicknesses less than 0.5 mm. Micro-welding techniques can be applied to join both similar and dissimilar materials combinations. Here are some key applications of microjoining today:
Power electronics for electric vehicles (EVs). The integration of small-scale components, such as chips, transistors, resistors, capacitors, and inductors, is a critical requirement for EV production. Micro-scale joining techniques can address the issues and enable further development of compact power electronics systems for EVs.
Medical technologies. With biomedical and electronic devices now smaller and more intricate than ever before, the task of joining materials for these devices is more complex. To meet the demands of this rapidly evolving landscape, specialized joining processes are necessitated.
Energy storage systems. The integration of batteries and interconnects at a small scale is essential for the advancement of energy storage systems. Successful assembly requires precise and robust joining techniques to ensure optimal performance, safety, and longevity.
For over 30 years, EWI has been developing and applying microjoining technologies to individual customer applications. Our systems include ultrasonic and thermosonic bonders, micro-TIG welders, precision resistance welders, ultrasonic welders, resistance reflow soldering and controlled-atmosphere furnaces. Our capabilities are described below:
Pulsed Arc Welding
Pulsed arc welding, a contactless process, involves striking an electrical arc between an electrode and the target component that produces a concentrated and high-energy density, leading to elevated local temperatures suitable for welding purposes. A precise power supply connected to a retracting welding electrode generates a brief but intense burst of energy. This technique welds metals with minimal heating of the component and is unaffected by electrical conductivity and optical reflectivity.
Pulsed arc welding can be used to join battery materials in pack assemblies. The technique is also suitable for welding very thin sheets as well as magnet wire for higher temperature coils and other wire-based applications. The ability to achieve precise and controlled welds while minimizing heat input makes pulsed arc welding an advantageous choice in these contexts.
Micro-resistance Welding
Fig. 1: Micro-resistance and micro-TIG welding system
Micro-resistance welding is also appropriate for joining small components with high precision. The technique applies electric current and pressure to create a localized heat zone that fuses the materials together. The two materials to be joined are placed in contact, usually clamped with the welding electrodes themselves under a pre-defined force. An electric current is passed through the workpieces, generating resistance-based heating. The combination of heat and pressure creates the bond. Bonding may be either in the solid state (caused by deformation of materials) or from the creation of a fused (melted) nugget. A typical small-scale resistance welding system is shown in Figure 1.
Micro-resistance welding provides precise and controlled heat input. The heat-affected zone is localized and minimal which helps prevent damage to nearby sensitive materials. This level of control is crucial in microjoining applications, where even slight temperature variations can have significant impacts. The associated limited temperature fields are also critical for minimizing distortion associated with welding.
Today’s micro-resistance welding systems offer pulse shaping and on-board statistical control capabilities. The former can be effective for challenging resistance welding applications. The latter is a core feature for ongoing quality control strategies, facilitating consistent product performance in high-volume applications.
Micro-resistance welding, useful for both similar and dissimilar material combinations, has been applied across the electronics, medical devices, automotive, aerospace industries. Common applications include the assembly of miniature sensors, micro-connectors, fine wires, micro-electronics, and medical implants.
Percussion Welding
Percussion welding is a unique resistance-based process in which expulsion of metal at the contact surfaces of the opposing workpieces creates residual liquid films that are joined when subsequently pressed together. Percussion action from the implied expulsion event may be caused by using an ignitor tip on one of the components or by rapidly bringing the workpieces together under an applied voltage potential. In either case, once percussion occurs there is an established arc that rapidly expands radially across the workpiece interfaces under the influence of the magnetic field associated with the secondary winding. This expanding arc melts a small layer on each workpiece. The pieces are rapidly brought together, and bonding occurs. Since percussion welding occurs in micro-seconds, the consolidated parts undergo rapid solidification, allowing joining of difficult to bond and dissimilar materials.
Typical percussion welding equipment (shown in Figure 2) most commonly employs capacitors to supply the energy to create and sustain the arc through the process. However, the use of half-cycle alternating power is also used. In fact, the technology is possible with any source with sufficient voltage to cause percussive action within the micro-second time period. Of note, percussion welding is typically done under relatively low forces compared to other resistance welding processes. Here, the force is only required to accelerate the parts after arc initiation, as well as retain the workpiece after contact allowing rapid solidification.
Fig 2: Percussion welding system
Percussion welding applications include tab attachments in batteries, filament joining to assembly of dental drills, and applying electrical contacts. Percussion welding can be effectively applied to components as small as tens of microns in diameter to those in excess of tens of millimeters. It is used with a wide range of materials (aluminum, copper, nickel alloys, Nitinol, refractory metals), as well as dissimilar combinations.
Ultrasonic Welding
Ultrasonic welding offers numerous advantages in terms of speed, precision, and effectiveness. It involves the application of high-frequency ultrasonic vibrations to create frictional heat at the interface between the components to be joined. In this process, the ultrasonic vibrations and heat soften the materials, which then deforms and shears local surface asperities, disperses interface contaminants, brings metal-to-metal contact, and bonds the surfaces together under pressure, to form a strong bond.
In small-scale devices (e.g., electronic components, microelectromechanical systems, medical devices), ultrasonic welding offers several benefits. First, as a solid-state welding process, it generates heat lower than the melting point of the metal which reduces the occurance of defects. The process does not require the use of additional materials like adhesives or solder, reducing the risk of contamination or the need for extra processing steps. This makes it particularly suitable for applications where cleanliness and minimal residue are critical.
Second, ultrasonic welding is fast and efficient, often achieving joining within fraction of a second. This rapid operation is optimal for high-volume production scenarios where time is of the essence. Third, the precise control of the ultrasonic vibrations allows for selective welding of specific areas or delicate components without causing damage to surrounding materials. The localized nature of ultrasonic welding makes it ideal for joining small-scale devices with intricate geometries or tight tolerances. As a solid-state process, it enables the bonding of dissimilar metals, such as aluminum, copper, etc., which may have different melting points or thermal properties. And finally, the process can be easily automated, ensuring consistency and repeatability in production, while its energy efficiency and low operating costs make it an economical choice.
Ultrasonic soldering is a variant of traditional iron soldering in which the ultrasonic vibration from the soldering iron produces cavitation bubbles in the liquid solder. When the bubbles collapse, the mechanical motion abrasively removes the surface oxides from the metal to be soldered. Once this occurs, the liquid solder can bond to the metal substrate. In both cases, the soldering iron tips are heated and keep the solder liquid or molten on the tip. Ultrasonic soldering can be used for joining dissimilar materials such as metals, ceramics, glass, etc. However, all solders can be used with ultrasonic soldering, including lead-free and zinc-based solders.
EWI can help you develop and implement innovative, microjoining processes tailored to your needs, as well as assist with material selection, feasibility trials, process optimization, cost analysis, and technology transfer. For more details, contact Surekha Yadav, [email protected].
We are pleased to welcome Wolfspeed, Inc., to EWI membership. The international company, based in Durham, North Carolina, is a semiconductor company focused on silicon carbide and GaN technologies.
