The grain refining action of fine TiB2 particles in the electrolytic low-titanium aluminum with Al–4B addition

The settlements and the grain refining action of TiB2 particles in the melt of electrolytic low-titanium aluminum (ELTA) with Al–4B addition were investigated. The results show that numerous fine TiB2 particles will be formed when Al–4B master alloy is added into the melt of ELTA at the Ti/B mass ratio of 5:1. Because of their fine sizes, though there are also TiB2 particle settlements, there will still be more TiB2 particles being suspended in the melt of the ELTA with Al–4B addition than in the melt of the pure Al with Al–5Ti–1B addition at a given Ti addition level. These fine TiB2 particles, together with the titanium atoms left in the melt, will form more heterogeneous nucleation sites during solidification of the melt, improving the grain refining efficiency and the fading-resisting ability obviously. Comparing with the method of adding Al–5Ti–1B into pure Al, the present method has advantages in resulting in the formation of fine TiB2 particles and preventing their settlements.