Microscale Solid-state Metal Additive Manufacturing using Laser-induced Supersonic Impact Printing

Among metal additive manufacturing (AM) processes, solid-state AM (SSAM) technique provides distinct advantages for near-net-shape fabrication of metallic components towards widespread applications. In this study, we introduced a new SSAM approach, named laser-induced supersonic impact printing (LISIP), which utilizes laser-induced high-velocity impact to cause significant adiabatic shearing at the flyer-substrate bonding interfaces, enabling three-dimensional (3D) metal printing under ambient conditions. Experiments were conducted to investigate LISIP’s capabilities, particularly for multi-layered micro-lamination of metal structures, and SSAM of dissimilar materials. In addition, direct on-demand metal writing was demonstrated to elucidate potential application of the process in micro-scale device fabrication. Various metal foils, including steel, Cu, Al, and Ti alloys, were used for the experiments. Key experimental parameters in LISIP, including laser intensity and impact distance were adjusted based on desired interfacial bonding characteristics. Microstructural analysis of bonding interfaces provided insights into microstructure evolution dominated by adiabatic shearing and dynamic grain refinement. The interfacial bonding strength was assessed utilizing lap shear tests. Experimental investigations exhibit the exceptional capability of LISIP to obtain high-quality interfacial bonds among various materials.