中文摘要：

针对气压驱动金属微滴按需喷射系统产生的微滴尺寸较小、断裂过程持续时间短,其关键参数不易直接测量的问题,构建了基于延时触发的金属微滴喷射过程图像采集系统。使用直径为200μm喷嘴,在系统稳定喷射情况下,对锡铅合金（60%Sn～40%Pb）微滴的形成和喷射过程进行图像采集、机理分析及关键参数测量研究。实验结果表明：通过将不同延时时刻的采集图像进行组合,可以再现按需喷射系统微滴形成的动态过程及其形态变化;测得了各时刻微滴的位置坐标和直径,计算出微滴平均飞行速度和喷射方向;揭示了金属微滴成形机理和随着飞行距离增大,微滴发散愈剧烈的变化趋势。

英文摘要：

It is difficult to directly measure the key parameters of metal droplets during the spraying process, be- cause the size of metal droplet is small and the rupture process is short duration based on the principle of pneumatic drop-on-demand generation. In order to solve this problem, the image acquisition system for the metal droplet form- ing process was constructed based on delay trigger method. Sn-Pb alloy （60% Sn -40% Pb） droplet spray experi- ments had been conducted with a generator nozzle of 200μm in diameter. The steady spray process was captured by the image acquisition system, then the forming mechanism of the metal droplet was analyzed and the key parameters were measured. The results show that the spraying process of metal droplet can be reappeared by combining differ- ent photographs of delay time. The coordinates and diameter of droplets were obtained in different delay times, and the flight velocity and deviation angle of droplets were calculated. The generating mechanic of metal droplets was revealed, and the change trends of droplet divergent was predicted along with the increasing of flight distance.