Orientation and Microstructure Evolution of Al-Al2Cu Regular Eutectic Lamellar Bifurcating in an Abruptly Changing Velocity under Directional Solidification

Abstract

In an abruptly changing velocity under directional solidification, microstructures and the growth orientation of Al-Al2Cu eutectic lamellar were characterized. The change in solidification rate led to an interfacial instability, which results in a bifurcation of the eutectic lamella into new, refined lamellae. The growth orientation of the eutectic Al2Cu phase was also only in its (001) direction and more strongly oriented to the heat flow direction. The results suggest that the eutectic lamellar Al-Al2Cu bifurcation and the spacing adjustment may be caused by the rate determining lateral diffusion of the solutes after interfacial instability.

Synthesis, Microstructure, and Electrical Conductivity of Eutectic Composites in MF2–RF3 (M = Ca, Sr, Ba; R = La–Nd) Systems

“…Composite materials with a periodic lamellar or rod microstructure can be synthesized by directional solidification of eutectic melts. Directional crystallization makes it possible to control the composite microstructure [8,9]. Composite materials exhibit functional characteristics that are not an additive combination of their constituent phases properties and are not inherent in the original components.…”

“…To date, eutectics of metallic [8,9,12], oxide [3][4][5][13][14][15][16], carbide [17], halide (including fluoride) [16,[18][19][20][21][22][23][24][25][26][27][28][29], and some other systems [30] have been fabricated by the directed crystallization technique. Most of these materials were obtained for the purpose of research in the fields of materials science and technology, photonics, and high-energy physics.…”