Yu Jilong, Zhang Daicong, Guo Wei, Jing Chunhui, Xiao Yuan
School of Mechanical & Electronic Engineering, Xi'an Polytechnic University, Xi'an 710048, China.
Micromachines (Basel). 2024 Sep 10;15(9):1139. doi: 10.3390/mi15091139.
Metal micro-droplet ejection technology has attracted attention for its potential applications in the rapid prototyping of micro-metal parts and microelectronic packaging. The current micro-droplet ejection device developed based on this technology faces challenges such as the requirement of a micro-oxygen ejection environment, a complex feeding structure, and high costs. Therefore, a drop-on-demand droplet generator for metallic pellets with impact feed ejection is designed in this paper. This device has a simple and compact structure, does not require a high-cost heat source, and can perform drop-on-demand ejection of metallic pellets in an atmospheric environment. A micro-channel feeding method based on piezoelectric ceramic actuator drives is proposed. A rigid dynamics metallic pellet flight trajectory model is established to analyze the relationships between the driving voltage and the flight trajectory of the pellets. With the help of Fluent to simulate and analyze the melting and ejection processes of the pellets inside the nozzle, the changes in the variable parameters of the flow field in the process of the melting and flight of a single molten drop are studied. The droplet generator produces stable droplets with a 500 µs pulse width and 1100 mm/s initial velocity of the projectile. The simulation results show that a single projectile has to go through three stages including feeding, melting, and ejecting, which take 39.5 ms, 7.85 ms, and 17.65 ms. The total simulation time is 65.0 ms. It is expected that the injection frequency of the metal projectile droplet-generating device will reach 15 Hz.
金属微滴喷射技术因其在微金属零件快速成型和微电子封装方面的潜在应用而备受关注。目前基于该技术开发的微滴喷射装置面临诸如需要微氧喷射环境、进料结构复杂以及成本高等挑战。因此，本文设计了一种具有冲击进料喷射功能的按需滴下式金属颗粒液滴发生器。该装置结构简单紧凑，不需要高成本的热源，并且能够在大气环境中进行按需滴下式金属颗粒喷射。提出了一种基于压电陶瓷致动器驱动的微通道进料方法。建立了刚性动力学金属颗粒飞行轨迹模型，以分析驱动电压与颗粒飞行轨迹之间的关系。借助Fluent模拟和分析喷嘴内颗粒的熔化和喷射过程，研究了单个熔滴熔化和飞行过程中流场可变参数的变化。该液滴发生器产生脉宽为500 μs、弹丸初始速度为1100 mm/s的稳定液滴。模拟结果表明，单个弹丸要经历进料、熔化和喷射三个阶段，分别耗时39.5 ms、7.85 ms和17.65 ms。总模拟时间为65.0 ms。预计金属弹丸液滴发生装置的喷射频率将达到15 Hz。
