Interface investigations of alumina and aluminosilicate short-fiber-reinforced aluminum-alloy composites

The interfacial microstructures of alumina (Al2O3) and aluminosilicate (Al2 O3. SiO2) short-fiber-reinforced aluminum-alloy composites were studied by means of transmission electron microscopy (TEM). The experimental results s howed that the SiO2 content in the fiber has a marked effect on the interfa ce microstructures of the composites even though a silica binder is not use d. The reaction product MgAl2O4 spinel oxide was formed at the interface of the aluminosilicate-fiber-reinforce aluminum-alloy composite, however, no spinel oxide was observed at the interface of alumina-fiber-reinforced comp osite. The alumina fiber could act as a heterogeneous nucleation substrate for the primary silicon phase as a result of the low disregistry (5.62%) be tween the (0001) of delta -A1(2)O(3) and the (110) of silicon. (C) 2001 Els evier Science Ltd. All rights reserved.