Additive manufacturing of alkali-activated materials by laser-induced slip casting

The work focuses on the development of a laser-based process for the additive manufacturing of components with complex geometries from alkali-activated materials. The "Laser-Induced Slip Casting" (LIS) process, originally developed for the additive manufacturing of ceramics, was transferred to handle reactive suspensions such as alkali-activated fly ash and optimized for this pur-pose. In the LIS process, a suspension is layerwise applied and selectively treated with a laser. This produces a green body in the laser treated area, which can be easily removed from the suspension after finishing the printing-process and subsequently after-cured. The advantage of the alkali-activated materials over conventional cement-based binders is their ability to react quickly when heated, making them very suitable for the LIS additive manufacturing process. In addition, the alkali-activated binders have very high acid resistance when properly formulated, resulting in components with increased chemical resistance compared to conventional binders.