Abstract
In this study, carbon nanofiber (CNF) reinforced Al_2O_3 composites were fabricated. To fabricate uniformly-dispersed CNF/Al_2O_3 powder, electrostatic adsorption, which could increase the surface potential of CNFs, was applied. Al203 sol was then adsorbed onto the surface of CNFs uniformly. The mixed powder was sintered by spark plasma sintering under the pressure of 50 MPa at 1600℃ in Ar atmosphere. Fracture behavior of the specimen was evaluated by bending test, indentation test and fracture-surface observation. The results showed that the bending strength of specimen was lower than monolithic Al_2O_3. It might be because there were many pores and the interface between CNF and Al_2O_3 were relatively weak. However, a large number of pull-out and bridging of CNFs were observed by the fracture surface observation with a scanning electron microscope. This suggests that CNFs could improve the fracture toughness of the CNF reinforced Al_2O_3 composites.
