Analysing the thermal characteristics of LAMP joining

The increasing utilisation of different material groups (plastic, metal, ceramics) in our advanced construction provides many benefits, but the fastening process is a challenge. LAMP (Laser assisted metal plastic) joining is a new technique in fastening technology. It means an alternative process from the existing techniques like using adhesives, screwing, riveting etc. The authors have been dealing with this technology for years. In this research work some important thermal phenomena were analysed in order to understand the process of joining more thoroughly. The temperature of the steel partner was measured in case of different laser settings and experimental situations with two measuring techniques: thermocouple and infrared camera. The results show the effect of different influencing factors during heating and the applicability of different measuring methods. The received temperature values can be compared to the characteristic temperature of PMMA polymer (decomposition temperature) in order to determine the root cause of bubble forming in the polymer material. From the result the differences between the different applied laser pulse mode for the heating was also determined and it was possible to measure the heating rate during the laser process.