Effect of SiO2 content in Al2O3 on interfacial bonding strength of aiuminium/Al2O3 composite

Abstract

In this study, the interfacial bonding strength between pure aluminium or an aluminium alloy (Al-12Si-uCu-1Mg-2Ni) and Al2O3 containing 0-20 wt-%SiO2 was measured using a B scale Rockwell hardness indenter. The interface was analysed using scanning electron microscopy, Auger electron spectroscop, and X-ray diffraction. The results obtained were as follows. In the pure aluminiumtAl2O3 compostte the interfacial bonding strength was not strongly affected by the SiO2 additions, but the interfacial strength of the aluminium alloy/Al2O3 compostte could be significantly improved by small additions (2-5 wt-%) of SiO2 in the Al2O 3. Magnesium was the only alloying element to segregate at the interface. At the interface of the pure aluminium/Al2O 3-20SiO2 specimen, Al2O3 and silicon were detected, and MgAl2O4 and Al2O 3 were detected in the aluminium alloy/Al2O 3-20SiO2 specimen. The interfacial chemical reaction involving magnesium is believed to be important in increasing the interfacial bonding strength. ？ 1995 The Institute of Materials.