新型振动辅助粉末输送系统增材制造钴基合金/铜合金界面互锁结构

In the process of multi-material laser powder bed fusion (LPBF), a high-quality powder delivery is critical for the stability of the LPBF process and enhancing the quality of parts. A new type of ultrasonic vibration-assisted powder delivery system is designed. The frequency characteristics of the vibration-assisted module and the effect of needle diameter on powder dropping are investigated. A needle with a size of 0.3 mm is demonstrated to achieve the stale and well powder delivery. Three types of Co-based alloy/copper multi-material parts with different interlocking structures (i.e., sawtooth, sine, and rectangle) are fabricated by LPBF using the ultrasonic vibration-assisted powder delivery system, demonstrating the feasibility of the powder delivery system. Subsequently, the interface characteristics of three types of multi-material parts are investigated to analyze the macroscopic morphology, defects and the element distribution at the interface. The results show that the powder can be delivered stably with a frequency of 21 kHz by the vibration-assisted module. A mixing area of two materials are found at the interface of the multi-material parts. The forming quality of the sawtooth-shaped interlocking structure is higher than that of the sine- and rectangle- shaped interlocking structures, which showing a good interfacial bonding. The results may provide reference for the design of the powder delivery system and the metal multi-material interface structure.