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

ABSTRACT

In this work, we propose a new method (by remelting Al-5Ti-1B) to investigate the grain refinement mechansim. It is found that the morphology and size of TiAl₃ phase had little effect on the grain refinement of pure Al. Therefore, further experimental studies were carried out to understand the potency of TiB₂ particles. The high-resolution transmission electron microscopy (HRTEM) observation has confirmed the existence of an atomic layer on the surface of (0001) TiB₂, which is possibly a two-dimensional (2D) (1-12) TiAl₃. Crystallographic study indicates that it is a more suitable nucleation sites for α-Al than other particles. The TiB₂ particle with TiAl₃ 2D acts as the best effective nucleation sites for α-Al.

KEYWORDS:

• Grain refinement
• pure Al
• remelted Al-5Ti-1B
• nucleation
• TiB₂/TiAl₃

Disclosure statement

No potential conflict of interest was reported by the authors.