本研究以實驗的方式探討金屬複合粉末於氣體霧化製程之參數控制。在金屬噴霧中加入正向對衝氣流，以取代固體基板，改善噴霧特性；亦可當載體，添加欲複合之陶瓷粉末顆粒。探討其霧化特性及粉末分佈情形，研究參數包括：對衝氣體與金屬噴霧之動量比、對衝孔口之大小以及對衝氣體出口與噴嘴之距離。其次在對衝氣流中添加陶瓷粉末，探討陶瓷粉末顆粒濃度、顆粒大小對金屬複合粉末製程之影響。實驗結果顯示，當對衝動量比從0增加到0.30，則Dv50從17.3μm下降至7.5μm，且Dv90從42.7μm下降至19.9μm，顯示金屬噴霧在對衝氣流作用下可以產生20μm以下之超微粒金屬粉末。若在對衝氣流中加入SiO2粉末，令金屬噴霧液滴與SiO2粉末碰撞結合成金屬複合粉末，則在添加Dv50為25.9μm之SiO2粉末時，當混合濃度從0%增加至6.8%vol時，金屬複合粉末之Dv50從7.5μm遞增為25.0μm，且Dv90從19.9μm增加為57.84μm；在添加Dv50為4.1μm之SiO2粉末時，當混合濃度從0%增加至6.8%vol時，金屬複合粉末之Dv50從7.5μm遞增為11.6μm，且Dv90從19.9μm遞增加為30.2μm。顯示金屬噴霧液滴與SiO2粉末結合會使複合粉末粒徑增大，且隨所添加SiO2之濃度與粒徑而遞增。
關鍵字：噴霧製程、氣體對衝、複合粉末

This research investigates the parameters to control the production of composite metal powder in the atomization processes. The atomization process was enhanced using counter impinging jet flow instead of the solid substrate. Furthermore, the impinging flow was seeded with SiO2 powder to produce the composite metal-ceramic powder. The parameters of this study include the momentum ratio between the spray and the impinging flow, orifice of the impinging jet and the distance between nozzle and the impinging jet, number density and the size of the seeding particles. Results show the mean particle size Dv50 of the metal powder decreased from 17.3μm to 7.5μm as the momentum ratio was increased from 0.0 to 0.30. It indicates that the ultrafine metal powder can be produced using the impinging mechanism. Moreover, the composite powder can be produced when the impinging flow was seeded with SiO2 powders. For example, the mean particle size of the composite particles Dv50 increased from 7.5μm to 25.0μm as the impinging flow was seeded by SiO2 powders with number density ranging from 0% to 6.8%vol and particle size of 25.9μm. However, the particle size of the composite powder can be controlled by seeding with smaller particles. The mean particle size of the composite particles Dv50 increased from 7.5μm to 11.6μm as the impinging flow was seeded by SiO2 powders with number density ranging from 0% to 6.8%vol and particle size of 4.1μm.
Keyword:Gas atomization, gas impingement, composite powder

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