Usually, glue or rivets are used when joining metal and plastic objects. However, these methods have their drawbacks: the surfaces to be glued must be left alone for some time, so that the glue "seizes", which slows down the production process, and rivets can damage the plastic surface. In addition, large quantities of such joint materials are always required in mass production.
Engineers at the Fraunhofer Institute for Materials Science and Beam Technology (Germany) have developed a device that connects such components quickly and easily, thanks to a process called HeatPressCool-Integrative (HPCI).
Initially, the metal and plastic object are compressed at the place of the future connection. Then the metal is subjected to point induction heating, which in turn leads to partial melting of the plastic. At the same time, its surface layer penetrates into an array of tiny anchor structures that were previously laser-etched into the metal surface at the junction.
During the curing process, the plastic shrinks and forms a strong bond between the two structures. It is very important that the whole process takes only a few seconds.
The Institute's specialists are convinced that the device they have developed based on HPCI technology will find application in existing production lines, for example, in robotic manipulators, replacing spot welding guns.