Dispersion behavior of MgO, ZrO2, Al2O3, CaO-Al2O3 and MnO-SiO2 deoxidation particles during solidification of Fe-10mass%Ni alloy

Abstract

The growth mechanism of deoxidation particles during solidification and dispersion behavior in mircosegregation domain have been studied in the experiments where an Fe-10mass%Ni alloy deoxidized with Mg, Zr, Al, Ca or Mn/Si was cooled from 1 873 to 1 673 K at 50 K · min-1, followed by rapid quenching. In a plot of the mean particle size versus time elapsed in liquid state and a plot of the number of particles per unit area versus time, the particle growth during cooling and subsequent solidification can be explained by Ostwald ripening. The Al2O3 particles are pushed to the region of final solidification at lower cooling rate, but the MgO and ZrO2 particles are engulfed. Engulfment and pushing of particles are discussed based on the wetting/interfacial energy model and the critical velocity of particle engulfment and pushing transition. © 2006 ISIJ.