A new technique to refine pure aluminum by Al-Ti-C mold

A new technique to refine commercially pure aluminum was presented, in which the pure Al melt was cast into an Al-Ti-C mold after flowing through an Al-Ti-C launder in the presence of electromagnetic field, and the refinement effect was also investigated. The experimental results indicate that the chill surface of the ingots can be more effectively refined by Al-5Ti-0.4C mold than by Al-7Si mold. In the presence of electromagnetic field, the forced convection significantly modifies the flow pattern and temperature field, which leads to a substantial amelioration of the surface quality and a marked reduction of the grain size. A uniform and fine equiaxed as-cast structure was obtained when the melt flows through an Al-5Ti-0.4C launder before casting into the Al-5Ti-0.4C mold with electromagnetic vibration, and the main reason for this is that the launder wall and the mold wall become permanent and continuous nucleation substrates from which α-Al grains come forth and depart because of the presence of substantial TiC particles and electromagnetic vibration.