Crystallization of Al-Sc-Ti alloys at low cooling rates: morphology of intermetallic particles

A.B. Shubin, E.A. Popova, P.V. Kotenkov, E.A. Pastukhov

KEYWORDS:

aluminum, scandium, titanium, alloy, microstructure, intermetallic compound, cubic and tetragonal lattice, structure type

ABSTRACT:

The crystallization of the ternary Al–Sc–Ti alloys containing, %: Sc – up to 1.4, Ti – up to 0.9 was investigated. The consolidation rate was ~ 1-3 degree/min. The crucibles used had the height/diameter ratio of ~ 10, that caused the significant inhomogeneity of the Sc and Ti distribution along the height of crucibles. The intermetallides with different lattice type and different particles shape – from almost spherical to the dendritic were found to be in the ingots structure. The morphology of intermetallic compounds (IMC) Al3 (Sc1-xTix) with the “nuclear—shell” structure and the metastable intermetallides with the composition that is absent in the phase diagram were studied.