Influence of Sintering Process on Mechanical Properties of ZrO_2/TiB_2 Composite by In-Situ Synthesis

TiB2 was fabricated using TiC and B4C as raw materials,ZrO2/TiB2 composite ceramic materials which content of TiB2 20wt% was fabricated by in-situ synthesis.Influence of sintering process on mechanical properties including temperature,holding time and pressure has been studied.The results show that the bending strength of the composite ceramic materials is improved from 820 MPa to 980 MPa,and its fracture toughness is improved from 7.2 MPa·m1/2 to 9.4 MPa·m1/2 when temperature raised from 1650 ℃ to 1750 ℃,the bending strength and its fracture toughness are decreased when temperature raised to 1850 ℃.Microhardness is improved when temperature raised.Its fracture toughness is improved from 8.6 MPa·m1/2 to 9.4 MPa·m1/2 when holding time increased from 30 min to 45 min at sintering temperature 1750 ℃ and pressure 30 MPa,but the fracture toughness is decreased when holding time increased to 60 min,and the holding time has little more influence on bending strength and microhardness.The experimental results show that bending strength,microhardness,fracture toughness of ZrO2/TiB2 composite is 980 MPa,13.6 GPa,9.4 MPa·m1/2 respectively under the optimum sintering condition including temperature of 1750 ℃,holding time of 45 min and pressure of 30 MPa.