The detail microstructures of LaB6-ZrB2 composites were characterized using TEM and HRTEM. The directionally solidified ZrB2 fibers in the LaB6 matrix of  LaB6-ZrB2 eutectics exhibited at least three growth relationship systems. In addition to the previous report of a [001]LaB6/[00•1]ZrB2 relationship, [0¯11]LaB5/[001]ZrB2 and [1¯20]LaB6/[00•1]ZrB2 were identified. Unlike the [001]LaB6/[00•1]ZrB2 system, the interfaces of [0¯11]LaB6/[00•1]ZrB2 and [1¯20]LaB6/[00•1]ZrB2 exhibited non-coherent and clean interfaces. Neither glassy phase nor reaction products were found at the interfaces.

Microstructural Characterization of LaB6-ZrB2 Eutectic Composites. Wang, S.C., Wei, W.C.J., Zhang, L.T.: Key Engineering Materials, 2003, 249, 101-4