采用以脉冲为微流动基本形态、脉冲当地惯性力为主动力的微流体数字化技术进行了金属微粉体(作为流体)脉冲输送微特性的实验，以解决激光金属粉体融覆沉积工艺中微粉体的精确稳定输送问题。建立了金属微粉体脉冲输送系统；以角形铬粉为实验材料，实验研究了驱动电压U、频率f、微喷嘴内径d、输送角度θ 等4种系统参量对铬粉脉冲输送微特性(粉体输送率和输送稳定性)的影响规律；以此规律为依据，确定和选择铬粉脉冲输送的系统参量，验证粉体微输送效果。实验显示，金属微粉体脉冲输送系统具有精确稳定的脉冲输送微特性，表征输送稳定性的变异系数C·V<7%，铬粉输送率Q可达每秒几十微克量级。结果表明：微流体数字化技术可实现金属微粉体的脉冲精确稳定输送；提出的研究方法可用于不同工程应用背景的微粉体脉冲输送的理论和实验研究。

To achieve the stable and precise transfer of micro metallic powders in the laser microcladding fabrication,micro characteristics of micro metallic powder transfer, called pulse-transfer are studied based on a new principle of microfluidic drive and control, in which microfluidic flows are driven by the pulsed local inertia force in micro channels. By using this technique, the flow of microfluidics can be controlled in pulse (or digital) demands. An experimental system of pulse-transfer for micro metallic powders is built to determine influencing rules of four system parameters, voltage amplitude U, frequence f, the inner diameter d of micro-nozzle, and the angle of transfer θ, on micro characteristics (powder transfer rate and stablity) of irregular micro chromium powders. The system parameters are optimized according to the influencing rules for transferring irregular micro chromium powders, and the effects of powder transfer are experimentally investigated. Experimental results indicate that the pulse-transfer system has excellent micro characteristics, and its powder transfer rate Q is within a few ten μg per second and relative stadard deviation C·V for evaluating transfer stability is smaller than 7%. The transfer of micro metallic powders with greater stability and precision is experimentally verified by using the technique of microfluidic digitalization,which demonstrates that the research method can be applied to experimental and theoretical studies of micro powder transfer in different fields of engineering.