Grain Refinement Efficiency in Commercial-Purity Aluminum Influenced by the Addition of Al-4Ti Master Alloys with Varying TiAl 3 Particles

摘要

A series of Al-4Ti master alloys with various TiAl 3 particles were prepared via pouring the pure aluminum added with K 2 TiF 6 or sponge titanium into three different molds made of graphite, copper, and sand. The microstructure and morphology of TiAl 3 particles were characterized and analyzed by scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS). The microstructure of TiAl 3 particles in Al-4Ti master alloys and their grain refinement efficiency in commercial-purity aluminum were investigated in this study. Results show that there were three different morphologies of TiAl 3 particles in Al-4Ti master alloys: petal-like structures, blocky structures, and flaky structures. The Al-4Ti master alloy with blocky TiAl 3 particles had better and more stable grain refinement efficiency than the master alloys with petal-like and flaky TiAl 3 particles. The average grain size of the refined commercial-purity aluminum always hereditarily followed the size of the original TiAl 3 particles. In addition, the grain refinement efficiency of Al-4Ti master alloys with the same morphology, size, and distribution of TiAl 3 particles prepared through different processes was almost identical.