Mechanical properties and microstructure evolution of Ti/Al2O3 cermet composite with CeO2 addition

摘要

The composites with CeO2 addition varied from 0 vol.% to 5 vol.% were sintered at 1420 degrees C under an applied pressure of 30 MPa for 60 min. The results of mechanical tests showed that CeO2 is useful for improving mechanical properties, but excessive addition (>3 vol.%) will deteriorate the composite; The highest values of relative density, Vickers harness, flexural strength and fracture toughness were recorded for the sample with 3 vol.% addition, which produced 97.6%, 15.7 MPa, 406.5 MPa and 6.36 MPa m(1/2). It can been seen from the SEM images and EDX analysis that the abnormal rod-like crystals appeared among Al2O3 grains. These unusual grains were confirmed as the solid solution of Ce-Al-O. The XRD revealed the crystalline phase and the transformation of grain growth trend of Ti/Al2O3 cermet composite. Moreover, the relationship of microstructure evolution and mechanical properties for the composite were illustrated. (C) 2014 Elsevier B.V. All rights reserved.