Fabrication of 3D metal-ceramic (Al-AlN) architectures using laser-powder bed fusion process

The potential of metal additive manufacturing for producing high conductivity materials and hybrid systems for thermal management in opto-, power and microelectronics has been investigated. Using the laser-based powder-bed fusion technology, the joining of ceramics (aluminum nitride) and metals (aluminum alloy: AlSi10Mg) has been studied with a focus on the fusion zone and the interlayer. Metallization of the ceramic surface with aluminum was applied to realize a stable process for forming metal-ceramic multilayer architectures. A sputtering process proved to be able to form a stiff interlayer and prevent direct contact of the laser beam with aluminum nitride. The bonding characteristics of aluminum nitride/aluminum alloy hybrid have been assessed, using scanning electron microscopy and energy dispersive X-ray spectroscopy. Owing to residual stress evolution during laser-powder bed fusion, process-induced material damage such as cracking at the binding zone was investigated and compared to residual stress simulations by which a correlation between process parameters, part geometry and the material failure could be established. Thus, the fabrication of crack-free metal-ceramics by a stable laser-powder bed fusion process was achieved.