Thermoplastic polyurethane (TPU) is one of the elastomeric polymers which has widespread applicability in various fields. Selective laser sintering (SLS) technology is gradually being used to manufacture actual end-use components and enables novel applications (footwear, healthcare mattresses, cable and wire) for TPU. This work aims to explore an optimum protocol (laser power, scanning speed and layer thickness) for SLS fabricated TPU components, and to evaluate the processability of TPU powder through systematically analyzing the morphological properties, structure, melting temperature, crystallization characteristics and tensile properties under different processing parameters. The optimum SLS processing parameters for TPU are laser speed of 3500 mm s −1 , laser power of 25 W and layer thickness of 0.1 mm. The tensile strength and superlative toughness of SLS-fabricated TPU samples can reach up to 20.02 MPa and 26 631 J mm −3 , respectively. The tensile strength of optimized SLS specimens (parameters: 20 W, 4500 mm s −1 , 0.15 mm) has been increased by 87.1% compared to that of reference.

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.

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