Resumen

GUEIJMAN, Sergio F; SCHVEZOV, Carlos E  y  ARES, Alicia E.. Analysis of interphase velocities during directional horizontal solidification of Zn-10%Al alloys. Rev. cienc. tecnol. [online]. 2010, n.13. ISSN 1851-7587.

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 metallurgy knowledge, 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 horizontally the hypereutectic Zn-10%Al (ZA10) alloy, 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 and the three others moving from the left): two [liquid/(solid+liquid)] interphases, namely [L/ (S+L)] or I_L interphases, two [(solid+liquid)/(eutectic+solid+liquid)] interphases, namely [(S+L)/(E+L)] or I_E, and two [(eutectic+solid+liquid)/solid] interphases, namely [(E+L)/S] interphases or I_S. The presence of these six interphases determined that the end of the solidification occured next to the geometric centre of the probes and seemed 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.

Palabras clave : One-directional solidification; Kinetics of interphases; Zn-10%Al alloys.