气压驱动金属微熔滴可控喷射及沉积精度分析?

Uniform Metal Droplet Produced by Pneumatic Generator with Controlled Spray Process and Analysis of the Droplet Deposition Accuracy

金属微滴按需喷射成形制造中,保证喷射系统按需产生均匀微滴和喷射沉积的位置精度是成形高质量金属零件的关键。采用试验研究的方法,分析喷嘴壁附着杂质对稳定喷射以及工艺参数对微滴均匀性的影响,并对喷射系统在可控喷射情况下按需产生的锡铅合金(Sn60%Pb40%)微滴尺寸分布进行分析;研究沉积高度变化对微滴沉积精度的影响。在上述研究基础上,通过选择合适的沉积高度,沉积制造一个6×6微滴阵列,并对微滴阵列的沉积精度进行分析。结果表明,所产生微滴的平均直径为321μm,尺寸标准偏差为2.897μm,约99%的颗粒分布在平均直径±2.8%附近区间内,分布较集中,均匀性较好;得到了发散距离随沉积高度增加而增大的变化趋势;成形的微滴阵列精度满足制造要求。为后续成形高质量微小金属零件提供必要的基础。

Generating uniform droplet on demand and assuring the accuracy of the droplet location are two key factors for forming high quality metal parts in the drop-on-demand droplet-based manufacturing process.The experimental methods are adopted to analyze the impact of particles lodging in the ejection nozzle on jet erratic and study the influence of process parameters on the uniformity of the droplets.Moreover,the size distribution of tin-lead alloy（Sn60%Pb40%） droplets obtained by using drop-on-demand spraying technique is discussed.The variation of the deposition accuracy with change of deposition distance is investigated.Furthermore,the accuracy of droplet location is discussed by depositing a 6×6 dots array on the substrate at appropriate deposition distance.The results show that the mean diameter and the corresponding standard deviation of the obtained droplets are 321 μm and 2.897 μm respectively.The diameters of about 99% of droplets is in the narrow range about ±2.8% of mean diameter,showing that the droplets with the narrow size distribution and good uniformity can be obtained.The offset distance also increases as the deposition distance increases.The accuracy of droplet deposited in dot array meets the requirement of metal droplet-based manufacturing.These works are useful for further study on the fabrication of minimized metal part.