Análisis de las velocidades de las interfases durante la solidificación direccional horizontal de aleaciones zn-10%al

Abstract

The prediction of the structures of solidification in binary alloys is important in order to advance in the knowledge of the field itself and in the field of materials in general. The validation and application of the numerical models that are being developed by our group intend to contribute to the expansion of the knowledge in the metallurgical area, since there are few studies in the literature about the prevailing conditions in which the columnar to equiaxed transition (CET) is produced when the conditions of solidification are horizontal, one-directional and in two different ways of solidification, and when the fronts of solidification of two surfaces facing each other meet. The present study aimed to solidify the hypereutectic Zn-10%Al (ZA10) alloy horizontally, when heat is predominantly extracted from both extremes of the samples. This gives six interphases of solidification moving in opposite directions (three moving from the right side and three moving from the left): two [liquid/(solid+liquid)] interphases, namely [L/(S+L)] or I interphases, two [(solid+liquid)/(eutectic+solid+liquid)] interphases, namely [(S+L)/(E+L)] or I, and two [(eutectic+solid+liquid)/solid] interphases, namely [(E+L)/S] interphases or IThe presence of these six interphases determines that the end of the solidification occurs next to the geometric centre of the probes and seems to be related to the presence of holes or cavities derived from the internal subsuperficial contraction. In this work, the speed and accelerations of all the interphases were determined as a function of time and position. The results obtained were compared with similar results obtained for hypoeutectic alloys solidified in similar conditions in a previous work.