Reconstruction of 2D Al₃Ti on TiB₂in an aluminium melt

Abstract

It has been widely considered that Al3Ti is involved in the aluminium nucleation on TiB2, although the mechanism has not been fully understood. In this paper molecular dynamics has been conducted to investigate this phenomenon at an atomistic scale. It was found that a two-dimensional Al3Ti layer may remain on TiB2 above the aluminium liquidus. In addition, the results showed that this 2D Al3Ti undergoes interface reconstruction by forming a triangular pattern. This triangular pattern consists of different alternative stacking sequences. The transition region between the triangles forms an area of strain concentration. By means of this mechanism, this interfacial Al3Ti layer stabilizes itself by localizing the large misfit strain between TiB2 and Al3Ti. This reconstruction is similar to the hdp-fcc interface reconstruction in other systems which has been observed experimentally [1].

A DFT Study of AlnTin (n = 2–12) Alloy Clusters

“…In addition, they also found that the TiAl 3 ‐like thin layer is thermodynamically stable on the layer of TiB 2 . Qin and Fan [ 16 ] further discovered that there was a TiAl 3 layer between Al liquid and TiB 2 through molecular dynamics (MD) simulation, and their results showed that TiAl 3 reconstructed the interface by forming a triangular pattern composed of different superposition sequences. The large mismatch strain localization between the reconstructed TiAl 3 and TiB 2 made TiB 2 more stable, and they speculated that there was an interesting stabilization mechanism for TiAl 3 .…”

Microstructure and refinement mechanism of TiB2/TiAl3 in remelted Al-5Ti-1B system

“…In recent years, some new model techniques have been applied to the study of heterogeneous nucleation, such as the density functional theory (DFT) and the molecular dynamics (MD) simulations [20,21]. Subsequently, MD simulation proposed by Qin and Fan has been proved that an atomic monolayer of (112) TiAl 3 might stabilise on the surface of TiB 2 at 860 K [22]. Another crucial aspect of heterogeneous nucleation is the coherence of the interfacial crystallographic characteristics between the solid/substrate.…”