Abstract
The microstructure of the aluminum borate whisker reinforced AC8A matrix composite fabricated by squeeze casting was examined with high resolution electron microscopy. Fine reaction products were observed on the whisker surface, which were identified to be MgAl2O4 (partly γ-Al2O3). Those reaction products introduced large strain inside to accomodate the lattice mismatch with a whisker and showed the crystallographic orientation relationship as follows:
{010} Al18B4O33//{111} MgAl2O4
[001] Al18B4O33//[110] MgAl2O4
No further reaction took place at the area covered with the reaction products. Steps were formed on the whisker with the reaction products on them. A thin amorphous-like layer was observed on the interface between the whisker and the matrix.
