In-situ process control strategies for selective laser melting

Selective Laser Melting (SLM) is an additive manufacturing process that has been attracting the attention of researchers and developers in academia and industry over the last two decades. The SLM manufacturing process is capable of producing sophisticated industrial tools and geometrically complex parts in fewer steps (near net-shape), thus saving resources compared to subtractive manufacturing processes. However, the current industry-scale platforms for manufacturing metal parts via SLM do not sufficiently exploit online feedback control strategies. There is still significant potential for advanced process control which can enhance the overall performance of the system, as well as enable sophisticated manufacture, for example via active control of microstructure to enhance part performance in geometrically complex parts. This paper presents a comparison between the performance of three well-known industrial control strategies, to illustrate strengths and weaknesses in addition to addressing the key challenges and identifying some research opportunities in the field.