IC12 - AddWRaP

Additive manufacturing using powder bed-based laser melting (PBF-LB) offers great potential for the production of tools, e.g. cutting tools with targeted coolant supply into the process zone. Compared to conventional manufacturing, there are hardly any geometric constraints, which allows channel design with maximum degrees of freedom and optimized cooling lubrication effect in the process zone. However, the surface quality in PBF-LB varies depending on the component orientation in the build space. Downskin- surfaces in particular exhibit increased roughness. However, these are unavoidable when manufacturing internal cooling channels with multi-axis orientation.

Aim, approach and benefit

The aim is to optimize additive manufacturing using PBF-LB in terms of reduced surface roughness. For this purpose, the interrelationships between particle size distribution (PGV) and process parameters are to be understood in order to enable a targeted influence. To begin with, a systematic selection of suitable PGVs is carried out using the tool steel 1.2709. To this end, monomodal PGVs are characterized with regard to their flow behavior and the expected powder bed density by means of simulations based on the Discrete Element Method (DEM) and the knowledge gained is transferred to multimodal PGVs specifically generated by mixing. The goal is to achieve a high powder bed density while maintaining sufficient powder flowability. Potentially suitable multimodal powders are processed in the PBF-LB and the resulting component states are extensively evaluated as a function of the manipulated variables and the surface orientation in the build space. Based on this, optimized process control variables are derived. Finally, the knowledge gained is transferred to a tool as a demonstrator in order to show the process optimization that can be universally transferred to the PBF-LB process.