\textbf{"Introduction/Purpose"}
By combining the joining process with the primary forming process, aluminum composite casting opens up great technological, economic and lightweight potential while simultaneously increasing the complexity of castable components. Compared with bolting or riveting, composite casting is characterized by homogeneous, material-specific force transmission between the cast and wrought-alloyed joining parts as well as by a single joining step and a shortened process chain. The automotive industry in particular benefits from the high lightweighting potential of aluminum-aluminum composite casting. By substituting steel with appropriate aluminum alloys such as A7075, which achieve strength values of some steels, both the weight and the residual stresses resulting from the previously different expansion coefficients of steel and aluminum can be reduced. Additional joining materials are not required, which facilitates recycling.
Many previous studies have referenced a material-to-material bond between the insert and the molten metal, as this bonding mechanism promises the highest strength. However, the naturally forming oxide layer poses a major challenge here, as it only melts at high temperatures of 2500°C and thus acts as a release layer. Therefore, this study investigates the approach of a form-fit with laser-structured aluminum inserts in the energy-saving die casting process to realize a stable composite, and explores an adjustment of the wetting and interlocking behavior with the molten aluminum and the resulting composite strength.

\textbf{"Methods"}
First, the interaction of different aluminum alloys with laser radiation was investigated using a commercially available infrared short-pulse laser system (\lambda = 1064 nm, 100 W), and then influencing parameters on structure formation were derived. Variation of laser surface structures of the inserts made of the high-strength alloy EN AW-7075 were cast on using the die casting method. The cold-chamber HDK system Buhler SC/N 66 and the casting alloy AlSi9Cu3 were used for this purpose. The produced composite casting specimens were tested in mechanical tensile tests and the interface was evaluated with metallographic specimens, microscopy and SEM.

\textbf{"Results}
It was shown that a stable, reproducible and strong bond of up to \textbf{"138 MPa} can be achieved by form-fit of insert and casting alone. Only upstream laser structuring of the inserts is required, which makes this process very attractive, especially for industrial applications.