Effect of mechanical vibration on semi-continuous casting of a hypereutectic A390 aluminum alloy

A simple mechanical vibration treatment during semi-continuous casting was used for production of hypereutectic A390 alloy billet suitable for thixoforming. Relatively low vibration frequencies and large amplitudes were employed in this treatment. Higher the frequency or larger the amplitude, primary, silicon particles macroscopically segregated at the upper part of the billets. Using the vibrations with the amplitudes of 2 and 4mm and the frequency of 20Hz, the billets with not only a nondendritic structure but also uniformly dispersed primary silicon particles in the matrix could be cast together with the better surface conditions than that of one without vibration.