A critical review of process monitoring for laser-based additive manufacturing

Additive manufacturing (AM) is a versatile, primary manufacturing method widely employed in aerospace, medical, and automotive industries. This environmentally friendly process involves complex phenomena, necessitating comprehensive monitoring for process insights. This review examines AM process monitoring systems, including optical cameras, thermography, and radiography. These technologies generate substantial data, enabling soft computing and machine learning applications for efficiency enhancement and process optimization. Focusing on laser-based AM, the review discusses existing monitoring methods, their limitations, and potential solutions. It explores intelligent AM systems and in-situ X-ray synchrotron techniques, highlighting the transformative potential of efficient process monitoring. The review briefly introduces AM classification, outlines current monitoring methods and their constraints, and proposes smart laser-based AM systems with an overview of applicable machine learning techniques. Finally, it presents plausible solutions to identified limitations and discusses future prospects, emphasizing the revolutionary impact of effective process monitoring on laser AM processes.