ULTRALAS | Ultrasonic welding of similar and dissimilar materials - Weldability and mechanical properties

Ultrasonic welding is a solid-state welding process using high-frequency oscillations and a static compressive force. Since the joint is created in the solid state, ultrasonic welding offers good weldability for dissimilar metal joints (e.g. copper to aluminium). Consequently, the process is widely used for the manufacture of batteries, electrical and electronic components.

The increasing electrification of transport equipment, the many new applications with integrated sensors and the development of all kinds of battery systems has led to the increasing use of ultrasonic welding. To date, however, there are no standards available for this process. This prevents the further implementation of the welding process in industry, and hence the benefits to be realised. This increased use of the welding process has created the need for a normative framework, to ensure that welding is performed in the most effective manner and that appropriate controls are performed over all aspects of implementation.

The objective of the project is to carry out research to generate all necessary knowledge and data for the future development of a standard for this welding process; such as information on mechanical properties, weldable materials, material combinations and dimensions, recommendations about the minimum tests to be carried out, suitable welding parameters and welding windows, quality requirements and acceptance criteria, and this for a wide range of materials.

These objectives are directly related to the topics that will be addressed in the future process standards. Research will be conducted about the following topics and recommendations will be formulated that can be used as a basis for the further development of the standards:

• welding knowledge, terminology and vocabulary,
• design of welded joints,
• qualification of welding operators,
• qualification of welding procedures,
• quality inspection and acceptance criteria.

The creation of a normative framework will help to further disseminate this innovative welding technology and lower the barriers to its implementation in industry. This project will provide companies with a significant competitive advantage in many ways:

• fast, environmentally friendly and economical welding technology,
• fast and cost-efficient joining of various materials, including difficult-to-weld metals or dissimilar joints,
• easy to automate welding technology, leading to a higher productivity and thus lower production costs, and an improved quality of welded joints and thus reduced rework, repair and waste.

Acknowledgements This pre-normalisation project is supported by FPS Economy (Project No. CCN/NBN/PN2023A68).