Rapid preparation of B4Cp/Al composites with homogeneous interface via ultrasound assisted casting method

Abstract

Ultrasound assisted casting method was applied in the rapid preparation of B4Cp/Al composites with the aim of obtaining homogeneous microstructure and improving mechanical properties with higher stability of composites. The process involved that the mixed B4C and K2TiF6 were added into molten Al at 800 °C, and then high-intensity ultrasound was introduced into the melt through an ultrasonic probe for 5 min. Experimental results showed that besides uniform distribution of B4C particles, a more homogeneous and continuous TiB2 layer could be formed on B4C particle surface due to the effects of ultrasound, which was beneficial for improving the dispersity and hindering the decomposition of B4C particle in the Al melt. Since the undercooling of melt and enhancement of diffusion of solutes could be induced by ultrasound, the nucleation and growth of TiB2 phase were effectively promoted, leading to the rapid formation of homogeneous TiB2 layer. Compared with the sample treated without ultrasound, the strength, ductility and performance stability of ultrasonically treated sample were improved significantly.