【作者】 何礼君； 张少明； 张曙光； 朱学新； 卢彩涛； 石力开；

【Author】 He Lijun , Zhang Shaoming, Zhang Shuguang, Zhu Xuexin, Lu Caitao, Shi Likai (National Engineering Research Center for Non-Ferrous Metals Composites , General Research Institute for Non-Fer-rous Metals , Beijing 100088, China)

【机构】 北京有色金属研究总院国家有色金属复合材料工程研究中心；

【摘要】 主要介绍了射流断裂的机制,并测量了金属锡熔体在不同喷嘴直径下的压力.速度曲线,在控制压力保证射流为层流的条件下,通过快速凝固的方法观察到金属射流表面波产生的现象。并以此为基础研究在层流射流条件下,金属熔体受一定激振频率后产生的表面波波长和激振频率的关系。得出金属射流在低频振动条件下(振动频率小于40 k),产生的表面波波长大小可以用如下关系式λ=A(σ/ρ)1/3f-2/3估算,对金属锡来讲,其中常数A的取值范围在5-8之间。并且当激振产生的表面波波长大于金属射流的周长时,金属射流会断裂为均匀的液滴。更多还原

【Abstract】 Metallic capillary stream break-up into droplets has recently attracted significant industrial and academic interest for applications requiring uniform metal particle production such as solder ball. The mechanism of capillary stream break-up into droplets was reviewed. The dependence of jet speed upon pressure and that of wavelength of surface wave upon vibration condition was studied through rapid solidification. It shows that under a certain vibration excitati-ons, surface wave appears on the jet and grows with time. If the wavelength of the surface wave is larger than the circumference of the jet, the jet will become unstable and break into a continuous series of droplets . The relation between wavelength of surface wave and vibration frequency can be predicted by the formula as λ = A (σ/ρ)1/3f2/3, where the value of A ranges from 5 to 8 for tin melt.更多还原