Successful Consolidation of Inoculant Alloy by Controlling Brazil Nut Effect and Capillary Force

Abstract

© 2022, The Korean Institute of Metals and Materials.Abstract: Novel inoculant alloy (IA) for dispersion of inoculants in molten metal was developed. By mixing powders of inoculant and matrix, 3 combinations of IAs having different inoculants (TiN, Ce2O3) and size of matrix powder (coarse, fine) were produced and added into molten metal the confirm dispersion and refining effect. Also, how these 2 variables can affect to dispersion was investigated. The combination of TiN + coarse matrix powder (T–C) does not melt and failed to disperse because of continuously-networked structure of TiN originated from larger size of matrix powder than the inoculant. The combination of Ce2O3 + fine matrix powder (C–F) made of powders of similar size melted, however, failed because Ce2O3 agglomerated because of capillary force varying with inoculant species. Comparing capillary forces for different inoculants shows that Ce2O3 has stronger agglomeration tendency than TiN. The combination of TiN + fine matrix powder (T–F) made of TiN having weaker agglomeration tendency and fine matrix powder disperse inoculants and refine solidification structure. Graphical Abstract: [Figure not available: see fulltext.]