Anti-fading study of Al-Ti-B by adding Ce on 6111 aluminum alloy

It is a practically significant issue to overcome the low efficiency and the short action time of Al-Ti-B master alloy for the grain refinement of aluminum alloys. In this paper, the phase relationship of the Al-Ti-B-Ce system, the effect of rare earth elements on the evolution of the morphology of the refining phases TiB 2 and Al 3 Ti, and the effect of the refiners on the microstructure and properties of the 6111 alloy are investigated. The experimental results show that the addition of rare earths introduces the rare earth phase Ti 2 Al 20 Ce into Al-Ti-B. The rare earth phase acts as an effective protective shell, reduces the free energy of Al 3 Ti, prevents further movement at the Solid/Liquid interface, and inhibits the aggregation and growth of the Al 3 Ti phase. By adsorbing on the surface of the TiB 2 phase, the rare earth reduces the surface energy and size of the TiB 2 phase, thus reducing the possibility of agglomeration. The fine and dispersed refining phase results in more effective nucleation sites in the melt, which can maintain grain refining for a long time and has better anti -fading effect. Therefore, the grain refiner Al-5Ti-B + Ce can effectively refine the grain of 6111 alloy, reduce the grain refinement fading shortcoming, and improve the strength and ductility of 6111 aluminum alloy.