TiC含量对无压烧结TiC/ZrO_(2)导电陶瓷复合材料微观结构和性能的影响

Effect of TiC Content on Microstructure and Performance of TiC/ZrO_(2)Conductive Ceramic Composites by Pressureless Sintering

以ZrO_(2)、TiC、TiO_(2)和酚醛树脂为原料,结合碳热还原反应原位生成TiC,通过无压烧结工艺制备TiC/ZrO_(2)导电陶瓷复合材料,研究了TiC质量分数(25%~40%)对陶瓷复合材料相对密度、微观结构、力学性能及导电性能的影响。结果表明:陶瓷复合材料由TiC相和t-ZrO_(2)相组成;随着TiC含量的增加,ZrO_(2)基体中的TiC颗粒逐渐相互连接而形成连续的网状结构,陶瓷复合材料的抗弯强度先增大后减小,硬度先降低后升高,相对密度、断裂韧性和电阻率不断减小;当TiC质量分数为30%时,陶瓷复合材料的综合性能最佳,其相对密度、抗弯强度、维氏硬度、断裂韧度和电阻率分别为97.42%,571 MPa,12.1 GPa,3.43 MPa·m^(1/2)和3.10×10^(-5)Ω·m。

TiC/ZrO_(2)conductive ceramic composites were prepared by pressureless sintering with ZrO_(2),TiC,TiO_(2)and phenolic resin as raw materials and combining with in-situ synthesized TiC by carbothermal reduction reaction.The effect of TiC mass fraction(25%-40%)on the relative density,microstructure,mechanical properties and conducivity of the ceramic composites were investigated.The results show that the ceramic composites consisted of TiC and t-ZrO_(2)phases.With increasing TiC content,the TiC particles in ZrO_(2)matrix gradually connected with each other and then formed a continuous network structure,the bending strength of the ceramic composites increased first and then decreased,the hardness decreased first and then increased,and the relative density,fracture toughness and resistivity decreased constantly.When the mass fraction of TiC was 30%,the ceramic composite had the best comprehensive properties,whose relative density,bending strength,Vickers hardness,fracture toughness and resistivity were 97.42%,571 MPa,12.1 GPa,3.43 MPa·m^(1/2)and 3.10×10^(-5)Ω·m,respectively.