Fabrication And Mechanical Properties Research Of Ti/Al₂O₃ Composite With CeO₂ Doped

Because of the excellent strength, toughness and low and medium temperature stability, metal/ceramic composite has already attracted widely attention, and it is used for aerospace, cutting tool, high-temperature transmission and bio-prosthesis. Compared with other sintering methods, the vacuum hot-pressing sintering achieve quickly low temperature sintering. In this study, the Ti/Al2O3 composite with CeO2 doped was fabricated by vacuum hot-pressing sintering, and the mechanical properties, microstructure and phase composition were investigated.Ti/Al2O3 composite with 1-5 vol% CeO2 doped was fabricated by vacuum hot-pressing sintering at 1420? under an applied pressure of 30 MPa for 60 min, and the mechanical properties, microstructure and phase composition were tested. The results showed that the addition of CeO2 improved the mechanical properties of T1/Al2O3 composite, and when the addition of CeO2 was 3vol%, the flexural strength, fracture toughness, vickers harness and relative density were 406.5 MPa,6.36 MPa·m1/2,15.7 GPa,97.6%. It can been seen from the XRD patterns and EDS analysis the reason of properties improvement of composite, and it was significantly affected by the presence of solid solution of Ce-Al-O.Based on the above experiments, the Ti/Al2O3 composite was fabricated in different sintering temperature (1420?-1480?) to discuss the effects of mechanical properties and sintering temperature. The results showed that the sintering temperature obviously affected the mechanical properties and microstructure of composite, and when the sintering temperature was 1450?, the relative density, vickers harness, flexural strength and fracture toughness were 98.7%,16.4 GPa,487.2 MPa and 6.88 MPa·m1/2.Laminated Ti/Al2O3 composite was fabricated by tape casting and vacuum hot-pressing sintering with intent to research mechanical properties and microstructure. The results showed that the flexural strength and fracture toughness improved according to the amount of layers. When the amount of layers was 35, the fracture toughness and flexural strength reached to 361.4 MPa and 9.72 MPa·m1/2, respectively. Based on the observation of microstructures, it was concluded that the improvement of mechanical properties was attributed to crack deflection, crack bifurcation, crack termination.The interfacial reaction and diffusion were discussed by the observation of elements O, Al and Ti due to the laminated structure of T1/Al2O3 composite. Furthermore, the addition of CeO2 improved the mechanical properties of laminated Ti/Al2O3 composite, and the relative density, fracture toughness and flexural strength reached to 96.7%,378.9 MPa and 9.74 MPa·m1/2.