Electromagnetic particle separation in the cold crucible melting with novel type bottom pouring nozzle
Electromagnetic particle separation in the cold crucible melting with novel type bottom pouring nozzle
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DOI：
10.1088/1757-899x/424/1/012029
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发表时间：
2018-10
期刊：
影响因子：
--
通讯作者：
V. Bojarevics;K. Pericleous
中科院分区：
文献类型：
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作者：
V. Bojarevics;K. Pericleous
冷坩埚熔炼技术被证明是最有效的获得活性金属铸件和生产高品质的金属粉末，用于航空航天，汽车和医疗应用。该技术的一个弱点是用于通过底部开口浇注熔融合金的石墨/陶瓷喷嘴，其寿命非常有限（几分钟），并增加了对高质量最终材料的污染。本文采用数学建模技术，以前验证了多个类似的情况下，研究一种新型的非自耗喷嘴制成的铜段。在动态熔化期间，喷嘴入口由与主熔体相同的合金的薄凝固层保护。研究了AC电磁（EM）场效应提取颗粒（杂质、沉淀物、氧化物、气泡等）的可能性。从融化。颗粒的动力学通过局部压力分布受到流体阻力、浮力、湍流脉动和电磁力的影响。电磁力导致熔体的高混合速率、过渡流动结构和湍流，有助于颗粒分散、运输和分离到期望的位置。本文论证了流动对随时间变化的粒子群向侧面凝固的“头骨”的输送和分离的影响。
The cold crucible melting technique is proven to be most effective to obtain reactive metal castings and produce high quality metal powders for aerospace, automotive and medical applications. A weak point of this technology is the graphite/ceramic nozzle used to pour the molten alloy through the bottom opening, which has very limited life time (several minutes) and adds contamination to the high quality final material. The paper uses the mathematical modelling technique, previously validated on multiple similar cases, to investigate a new type of non-consumable nozzle made of copper segments. During the dynamic melting the nozzle entrance is protected by a thin solidifying layer of the same alloy as the main melt. The AC electromagnetic (EM) field effects are investigated for the possibility to extract particles (impurities, precipitates, oxides, bubbles, etc.) from the melt. The dynamics of particles are affected by the hydrodynamic drag, buoyancy, turbulent fluctuations and the EM force via the local pressure distribution. The EM force leads to high mixing rates, transitional flow structures and turbulence of the melt, contributing to the particle dispersion, transport and separation to a desired location. The paper demonstrates effects of flow on the time dependent particle ‘swarm’ transport and separation to the side solidified ‘skull’.