Materials' fundamental issues of laser additive manufacturing for high-performance large metallic components

The advantages, state of the art and technological challenges of laser melting deposition additive manufacturing for high-performance large metallic components are briefly reviewed. The unique technological merits of laser additive manufacturing for high-performance large metallic components characterized by digital integration of “advanced materials processing”, “complex structure direct manufacturing” and “controlling shape and performance” are systematically discussed. It is emphasized that further development and industrial applications of the revolutionary manufacturing technology will greatly rely on the intensive basic research on those general non-equilibrium materials fundamental issues inherent to the additive manufacturing process such as laser/metal interaction behavior and laser absorbing mechanisms, forming mechanisms and mechanical behavior of internal metallurgical defects, constrained rapid solidification kinetics of moving melt-pool and grain morphological selection characteristics of deposited components, non-steady cyclic solid-state phase transformation kinetics and microstructure formation behavior, non-linear thermal history/thermal stress coupling behavior and distortion and cracking, etc.