Interfacial structure in TiB2/Al composite after high speed impact

Abstract

Interfacial structure in 55%TiB2/Al composite before and after high speed impact was investigated in detail. It is found that there is no stacking fault in original TiB2 particle before fabrication or in TiB2 particle in composite. However, after the composite is impacted by 1.2mm projectile with the velocity of 2.5km/s, stacking fault forms along the (0001) plane around the edge of TiB2 particle and grows with a step-like epitaxial way, resulting from the high pressure of shock wave. At the bottom of crater in the target, Al matrix around the TiB2 particle was molten and then oxidated, which results in the formation of AlxO1−x (x<1) phase between TiB2 particle and Al matrix. It is found that TiB2 particle and AlxO1−x phase combine well and have no reacted layer at the interface and there exists an orientation between two phases: [0 1 1¯ 0]TiB2//[3 1 0]AlxO1−x, (2¯ 1 1 0)TiB2//(0 0 2)AlxO1−x.