Influence of growth velocity v and temperature gradient G on the interlamellar spacing λ of FeC unidirectionally crystallized eutectic

The paper presents results of investigations concerning the influence of the growth velocity (v) and temperature gradient (G) on the interlamellar spacing (λ) in an irregular iron-carbon (Fe-C) eutectic unidirectionally crystalized. The aim of this study was to verify the growth model of D.J. Fisher and W. Kurz and to determine the relationship λ = f(v, G) based on experimental and numerical analysis. The crystallization process was carried out using the Bridgman-Stockbarger method with liquid metal cooling (LMC), and the structure was studied using optical microscopy and scanning electron microscope. In parallel, numerical simulations were performed in ProCAST to determine the temperature gradient in the liquid at the crystallisation front. The results showed that increasing the growth velocity at constant G leads to a decrease in the interlamellar spacing λ, while at constant velocity a decrease in G results in an increase in λ. The experimental data obtained showed good agreement with the results of mathematical modelling, confirming the suitability of the W. Kurz and D.J. Fisher model in describing the crystallisation of irregular Fe-C eutectics alloys.