With a practical cold joining process, high-strength steel bonded joints can be separated while preserving the material. This is particularly interesting for the repair of multi-material car bodies.
Researchers at Hamm-Lippstadt University of Applied Sciences and Paderborn University have developed a cold joining process that can be used to release adhesive bonds quickly, easily and gently using low temperatures. Using a dry ice blasting system, they cool the joining zone to around -60 °C for a short time. They use a mixture of CO2 and ethanol, which remains on the component and cools the underlying adhesive layer. According to the researchers, this allows the bond to be released efficiently and with little force, while the joining partners themselves remain protected.
Until now, high-strength, crash-resistant bonded joints had to be laboriously removed at relatively high temperatures of 350 to 500 °C, for example using a special hot-air gun and bodywork chisels. Components that are actually reusable, for example in multi-material car bodies, are often deformed by the mechanical stress. According to Rainer Salomon, Managing Director of the AiF Research Association for Steel Applications, which funded the development, the technology is suitable for large-scale production and represents a major advantage in the material cycle. The researchers involved in the development are among the three finalist teams for the Otto von Guericke Prize 2023.