Author:

Abstract:

Observation of the melt pool, formed during a normal Selective Laser Melting (SLM) build process, shows a non-uniform melt pool intensity distribution throughout one layer and scan track. The associated variation of the melt pool intensity can cause unwanted defects (e.g. pores). The change in melt pool intensity and possible defects cannot only be observed within one layer but will propagate itself throughout all the layers. To counteract the change in melt pool characteristics, a system identification was performed on the melt pool intensity, during several layers, in function of the laser power. The system identification provides a mathematical model of the melt pool intensity that was used for the development of a feedback controller. The benefit of the feedback controller was simulated.