In powder bed–based electron beam melting, complex components can already be manufactured today. However, classical line-based exposure strategies result in inhomogeneous temperature histories within individual layers and consequently in spatially varying material properties throughout the component.
The transition to point-based exposure strategies enables precise spatial and temporal control of the energy input and therefore represents a promising route toward homogeneous material properties across the entire build. The objective of this project is the development of an algorithm that determines an optimal exposure sequence from the virtually infinite number of possible point orders, while simultaneously accounting for machine-specific constraints and the thermal budget of the process.
The proposed approach allows uniform thermal histories within a layer while explicitly considering the finite deflection speed of the electron beam. In addition, the rigid grid binding of melting points at component boundaries can be relaxed and flexibly integrated into the exposure strategy. In combination with suitable three-dimensional point arrangements, this enables the omission of separately melted contour lines without compromising surface quality.
The resulting advantages are substantial: the elimination of a major defect source, reduced energy consumption and melting time, and significantly lower process development effort. The algorithm is applicable to arbitrary geometries and common point grid configurations and is used not only in a university research environment but also in large-scale industrial build jobs. The generation of machine-ready build files for components comprising up to 150 million individual points can be completed overnight on a dedicated in-house workstation.
These activities originated within the framework of the Collaborative Research Center SFB 814 “Additive Manufacturing” and now form the foundation for a broad range of subsequent research projects and funding proposals. The developed concepts and methods are being carried forward at both national and international levels and feed into ongoing and planned initiatives, including the ERC grant AMELI, thereby substantially advancing point-based exposure strategies in additive manufacturing.