中文摘要：

针对现有金属微滴按需喷射装置难以喷射产生小于喷嘴径向尺寸的微滴的问题，设计开发一种基于应力波驱动的新型金属微滴喷射装置，采用锡铅合金（Sn．质量分数40％Pb）在加热温度为300℃下进行了喷射试验，试验表明：当脉冲宽度5ms，脉冲频率5Hz，电磁冲击杆冲击行程以及传振杆下端距离喷嘴分别为3mill和1．5toni时，在同轴供气流量大于6L／min的气氛环境中，该喷射装置能够喷射产生平均直径约为喷嘴直径60％的金属微滴，且微滴尺寸标准方差为9．2um，证明应力波驱动金属微滴按需喷射装置能够喷射出小于喷嘴尺寸的微滴。试验结果也显示，在满足微滴喷射的条件下，微滴直径随着脉冲宽度的增大而线性增大，随着脉冲频率的增大而呈指数形式减小，且微滴喷射过程受到冲击杆行程S的影响，说明此装置在喷嘴尺寸不变的条件下，具有微滴尺寸可调节、易控制等优点，为金属微滴喷射技术的进一步应用奠定了基础。

英文摘要：

The metal droplet size is mainly determined by the nozzle size in the existing metal drop-on-demand （DOD） technologies. It is hard to spray metal micro droplets with diameter smaller than nozzle diameter by using those technologies. A novel metal droplet generator driven by stress wave is designed and developed to spray metal micro droplets without the limit of the nozzle size. Then the metal micro droplets generation experiment is carried out by using Sn-40%Pb alloy when the heating temperature and coaxial gas flow is about 300 ~C and more than 6 L/min, respectively. The experiment results show that the average diameter of droplets generated by the stress wave is approximately 60% of the nozzle size and the standard variation of droplet diameter is 9.2 gm when the pulse width is 5 ms, the pulse frequency is 5 Hz, the impact rod stroke is 3 mm and the distance between the vibration rod bottom and nozzle is 1.5 mm. The experiment results show the feasibility of the stress driven DOD generator. The experimental results also show that in the appropriate impact rod stroke range, the size of the droplet diameter increases linearly with the pulse width increases and exponentially decreases with the increase of pulse frequency, showing that it is easy to change the droplet size when the nozzle size is constant using the developed DOD generator. The research provides a novel method for generating droplets of which size is smaller than nozzle size. These works are useful for further application of metal droplet spray technology.