Abstract
Titanium oxide whisker reinforced aluminum matrix composites were fabricated by a powder metallurgical method. Our previous study on tensile properties of TiO2(N)/A1 composite indicated that the interfacial reaction occured considerably on the fabrication process, however, their tensile properties were nearly equal with those of SiC(W)/ Al composite.
In this study, fatigue strength was examined by rotating bending test, and the whisker /matrix interface structure was investigated by scanning electron microscope and X-ray diffraction method. For the TiO2(w)/A1 composite, TiO2 whisker changed to Ti2O3 after hot pressing and A1, Ti and A12O3 were produced after hot extrusion at the interfaces. Fatigue limit for the TiO2(R)/A1 composite increased about 50% compared with that of monolithic aluminum. Fatigue crack growth direction was diflected by the whisker and propagated in the matrix along the interface. This fact means that the resistance to crack initiation and propagation increased because the adhesion force between whisker and matrix was improved by the existence of reactants at the interface.
