Magnetic Pulse Welding (MPW) by electromagnetic compression is a solid-state welding technique favorable for the creation of strong metallurgical bonds between both similar and dissimilar metals. The process is based on the plastic deformation of one of the joining partners and the subsequent high velocity collision with the other joining partner. Due to the absence of external heat, brittle intermetallic phases and other heat induced defects are largely-avoided which makes the process especially suitable for multi-material joints applied in lightweight design. However, the stationary part must be able to withstand the harsh impact without inadmissibly permanent deformation. This is why mostly solid cylinders are used as parent parts, limiting the lightweight potential. The paper focuses on the MPW of aluminum (EN AW-6060) to steel (C45) tubes with and without supporting mandrel inside of the parent part. Experimental studies were performed in which the wall thickness of the parent steel part was reduced successively. The deformation behavior of both the flyer and parent parts was recorded during the experiments by a periscope-style photonic Doppler velocimetry (PDV) setup. It was found that defect-free MPW of aluminum tubes on steel tubes without supporting mandrel is generally possible but strongly depends on the characteristics of the electromagnetic pulse due to the initiation of elastic waves that may deteriorate the weld quality. Critical values for the parent wall thickness were deduced for various pulse shapes and joining partner geometries and the feasibility of supporting elements was investigated.
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