Interfacial structure of sub-micron Al2O3 particles in aluminum matrix

Abstract

The surfaces of ellipsoidal Al 2 O 3 particles with average size of 0.15 ¹m and the interfaces between the Al 2 O 3 particles and 1070Al were investigated by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM).The results show that the surfaces of Al 2 O 3 particles appear to be polyhedrons consisting of crystal planes with small angle, while every plane of the polyhedrons could be considered as a stepped structure composed of close-packed planes along the close-packed direction. The interfaces of the 0.15 ¹m Al 2 O 3 p/ 1070Al composite bond well, without any interfacial reaction products. It is proposed that there are several kinds of crystallographic orientation relationships between the aluminum matrix and Al 2 O 3 particles due to the polyhedral structure. In our study, such orientation relationships are found to be f110g Al kf N 1100g Al2O3 and h110i Al kh11 N 26i Al2O3 .