Effect of Warm Rolling on the Grain-Refining Performance of Al-5Ti-1B Grain Refiner in Al

The influence of warm rolling on the evolution of second-phase particles of the Al-5Ti-1B refiner and their effect on the grain refining of Al were studied by OM and SEM. The results showed that rolling causes fracture of both Al3Ti and TiB2 particles, as the reduction rate increased from 0% to 90%, the average size of Al3Ti and TiB2 particles were decreased from 40.29 µm ± 2 µm and 0.8 µm ± 0.1 μm to 25 µm ± 0.5 μm and 0.37 µm ±0.025μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm 0.025 \mu \mathrm{ m}$$\end{document} respectively. Also, it was found that warm rolling improves the grain-refining efficiency of the Al-5Ti-1B refiner. The enhanced grain-refining efficiency of the Al-5Ti-1B refiner is probably attributed to the increased amount of TiB2 particles being introduced into Al after warm rolling, which could provide more nucleation sites.