Research on mechanism of generating aluminum droplets smaller than the nozzle diameter by pneumatic drop-on-demand technology
Research on mechanism of generating aluminum droplets smaller than the nozzle diameter by pneumatic drop-on-demand technology
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DOI：
10.1007/s00170-017-0484-x
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
Song-yi Zhong;L. Qi;Wei Xiong;Jun Luo;Qing Xu
中科院分区：
文献类型：
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作者：
Song-yi Zhong;L. Qi;Wei Xiong;Jun Luo;Qing Xu
基于液滴的制造（DBM）工艺在直接制造金属零件方面具有巨大的潜力。为了提高DBM的实用性，减小液滴尺寸成为该领域的研究热点。本文提出了一种新型的射流驱动液滴发生器结构，并研究了其产生小于喷嘴直径的铝液滴的机理。通过模拟实验，研究了结构参数对液滴形成过程和液滴尺寸的影响。结果表明，喷嘴孔的高宽比（i）和入口孔与喷嘴孔的距离（H1）对液滴尺寸有显著影响，而入口孔直径对液滴尺寸影响不大。液滴小于喷嘴直径时，可以产生只有当i和H1分别为1和1毫米。在优化结构参数的基础上，研制了液滴发生器，并进行了液滴喷射实验。采用直径为500 μm的喷嘴，稳定地制备出平均直径为359.9 μm的铝液滴，并通过液滴的连续沉积制备出矩形管。结果表明，该新型发生器能够产生小液滴并直接制造零件。
Droplet-based manufacturing (DBM) process has great potential in directly fabricating metal parts. In order to enhance the practicability of DBM, decreasing droplet size becomes the research focus in this field. In the present work, a novel pneumatic-driven droplet generator structure was proposed and the mechanism of generating aluminum droplets smaller than the nozzle diameter was studied. By conducting simulation experiments, the effects of structure parameters on droplet formation process and droplet size were investigated. The results indicated that the aspect ratio of the nozzle hole (i) and the distance between inlet hole and nozzle hole (H1) had significant effects on droplet size while the diameter of the inlet hole had little effect. Droplets smaller than the nozzle diameter could be produced only wheniandH1were 1 and 1 mm, respectively. Based on the optimized structure parameters, a generator was developed and droplet-ejecting experiments were carried out. By using a nozzle with the diameter of 500 μm, aluminum droplets with the mean diameter of 359.9 μm were produced stably and then a rectangular tube was fabricated by depositing droplets sequentially. The results demonstrated the capability of the novel generator to produce small droplets and to fabricate parts directly.