Rapid preparation of B₄C_p/Al composites with homogeneous interface via ultrasound assisted casting method

Ultrasound assisted casting method was applied in the rapid preparation of B₄C_p/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.