Dynamic melting and impurity particle tracking in continuously adjustable AC magnetic field

International Symposium on Liquid Metal Processing & Casting 2015

材料科学;金属工艺学

Bojarevics, V.^1 ; Pericleous, K.^1

University of Greenwich, London

SE10 9LS, United Kingdom^1

关键词: AC magnetic fields;    Dynamic melting;    Electromagnetic forces;    Impurity particles;    Melting cycle;    Particle dispersion;    Particle transport;    Uniform magnetic fields;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/143/1/012020/pdf
DOI  :  10.1088/1757-899X/143/1/012020

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The analysis of semi-levitation melting is extended to account for the presence of particles (impurities, broken metal dendrite agglomerates, bubbles) during the full melting cycle simulated numerically using the pseudo-spectral schemes. The AC coil is dynamically moving with the melt front progress, while the generated Joule heat serves to enhance the melting rate. The electromagnetic force is decomposed into the time average and the oscillating parts. The time average effects on the particle transport are investigated previously using approximations derived for a locally uniform magnetic field. This paper presents expressions for the skin-layer type of the AC force containing also the pulsating part which contributes to the particle drag by the 'history' and 'added mass' contributions. The intense turbulence in the bulk of molten metal additionally contributes to the particle dispersion. The paper attempts to demonstrate the importance of each of the mentioned effects onto the particle transport during the melting until the final pouring stage. The method could be extended to similar AC field controlled melting/solidification processes.