High Reflectivity and Thermal Conductivity Ag–Cu Multi-Material Structures Fabricated via Laser Powder Bed Fusion: Formation Mechanisms, Interfacial Characteristics, and Molten Pool Behavior

Abstract

Ag and Cu have different advantages and are widely used in key fields due to their typical highly electrical and thermal conductive (HETC) properties. Laser powder bed fusion (LPBF), an innovative technology for manufacturing metallic multi-material components with high accuracy, has expanded the application of Ag–Cu in emerging high-tech fields. In this study, the multi-material sandwich structures of Ag7.5Cu/Cu10Sn/Ag7.5Cu were printed using LPBF, and the formation mechanism, interface characteristics, and molten pool behavior of the Ag7.5Cu/Cu10Sn (A/C) and Cu10Sn/Ag7.5Cu (C/A) interfaces were studied to reveal the influence of different building strategies. At the A/C interface, pre-printed Ag7.5Cu promoted Marangoni turbulence at a relatively low energy density (EA/C = 125 J/mm3). Due to the recoil pressure, the molten pool at the A/C interface transformed from a stable keyhole mode to an unstable keyhole mode. These phenomena promoted the extensive migration of elements, forming a wider diffusion zone and reduced thermal cracking. At the C/A interface, the molten pool was rationed from the conduction mode with more pores to the transition mode with fewer defects due to the high energy density (EC/A = 187.5 J/mm3). This work offers a theoretical reference for the fabrication of HETC multi-material structures via LPBF under similar conditions.

Four-Dimensional Micro/Nanorobots via Laser Photochemical Synthesis towards the Molecular Scale

“…By modulating a single laser beam to a point array or specific pattern, the fabrication efficiency or volume is ameliorated over one magnitude. In summary, the laser photochemical synthesis utilizes an optical setup of the digitalized laser additive manufacturing system [ 75 , 76 , 77 , 78 ] with precise optical components (focusing optical path, radio-frequency acoustic–optic modulator, 3D scanning system, large N.A. objective lens) to confine the photochemical reaction at the nanometric resolution, and is being developed by researchers from several fields.…”

Study on Laser-Electrochemical Hybrid Polishing of Selective Laser Melted 316L Stainless Steel

“…The 316L austenitic stainless steel is widely utilized in the fields of chemistry, marine engineering, food, and biomedicine due to its excellent mechanical properties and corrosion resistance [ 6 , 7 , 8 , 9 ]. Compared to conventional processes, SLM offers numerous advantages in preparing 316L SS, including high material utilization and the ability to fabricate complex structures within short fabrication cycles [ 10 , 11 , 12 ]. However, the inherent spheroidization effect, powder adhesion, and step effect in SLM result in poor surface roughness of the prepared parts [ 13 , 14 , 15 , 16 ], necessitating post-treatment and polishing to meet application requirements.…”

Silver Alloy Surface Modification for Mechanical Property Enhancement in Aviation and Transportation

“…Nevertheless, they present strong disadvantages in their relatively low wear resistance and hardness, which can be a problem for long-term usage, such as in switch elements. The combination of laser surface treatment and addition of different types of metallic powders in the surface layer has been identified as a possible solution for this [1][2][3].…”