TiN／Si3N4复相导电陶瓷的制备及其性能

Preparation and properties of TiN/Si_3N_4 multiphase electroconductive ceramics

以铁尾矿为主要原料经碳热还原氮化制成的Si3N4粉和高钛渣作为原料,常压烧结制备了TiN/Si3N4复相导电陶瓷。利用XRD对其相组成进行了表征,研究了初始原料中TiO2加入量对材料致密度、力学性能和导电性能的影响。结果表明,烧结产物主要由Si3N4和TiN组成,随初始原料中TiO2加入量的增加,烧结产物中TiN相含量增加;初始原料中TiO2加入量为25%(质量分数)时烧结试样的体积密度为3.32g/cm3,硬度为8.97GPa,抗弯强度为79MPa。最少需加入20%左右的TiO2,材料中的TiN才能形成导电网络,此时材料的电阻率为4.25×10-2Ω.cm。

TiN/Si3 N4 multiphase electroconductive ceramics were prepared by pressureless sintering from slag with high titanium and Si3N4 which was synthesized by the earbothermal reduction nitridation method using iron ore tailings. Phase constitutes were analyzed by XRD. The effect of TiO2 content in initial raw materials on phase econsitutes,densiIication,mechanical properties and electrical conductivity were studied. The results show that the sintered samples consist of Si3 N4 and TiN. The TiN phase enhances with the increase of TiO2 content in ini- tial materials. For the composite samples sintered at 1550℃ using raw materials containing 25wt% TiO2,hulk density, hardness and flexure strength are 3.32g/cm2 ,8.97GPa and 79MPa, respectively. The minimum amount of TiO2 in initial raw materials is 20% for the formation of eleetroconductive network in the composites, of which the electric resistivity is 4.25 × 10^-2Ω·cm.