Process Control for Selective Laser Melting - Opprtunities and Limitations

Additive Manufacturing (AM) technologies are increasingly used for final part production. Especially technologies for processing of metal, like Selective LaserMelting (SLM), arefocusedin this area. The shift from prototyping towards final part production results in enhanced requirements for repeatability and predictability of the part quality. Machine manufacturers offer process monitoring solutions for different aspects of the production process, like the powder bed surface, the melt pool, and the laser energy. Nevertheless, the significance of these systems is not fully proven and threshold values for the monitored process parameters have to be determined for each product individually. This impedes the development of suitable process control systems. The paper gives an overview ofexistingresearch approaches and available process monitoring systems for SLM and their applicability for predicting certain part characteristics. The existing solutions are evaluated based on own research results. Next, AM specific difficulties for the development of process control tools and possible solutions are discussed.