The effect of V on the morphology of TiB2 particles in as-cast aluminum composites

This study presents the modification effect of trace vanadium on the in-situ formed TiB2 particles in as-cast aluminum composites. With 0.2 wt.% V addition the morphology of TiB2 was modified from hexagonal platelet or irregular feather-like shape to hexagonal prism or rectangular prism with parallel growth steps along the c-axis. Meanwhile, V rich cores were detected in the center of TiB2 and the exposure of the high-index crystal plane (1101)TiB2 was detected in Al-0.2 wt.%V. Statistical analysis of the particle size and aspect distribution both in commercial Al and Al-0.2 wt.%V was conducted. The elemental distribution and scanning electron microscopy investigation revealed that VB2 may serve as the 2D-nucleus of TiB2 particles. The growth mechanism of TiB2 under the influence of V was explored.