不同烧结条件下V_2O_5对NiFe_2O_4基惰性阳极结构和性能的影响

采用两步冷压—烧结法制备了V_2O_5掺杂NiFe_2O_4尖晶石阳极材料,研究在不同烧结条件下,V_2O_5添加剂对NiFe_2O_4尖晶石结构和性能的影响。结果表明,向NiFe_2O_4陶瓷基体中引入V_2O_5后形成了低共熔点物质Ni_2FeVO_6,形成液相烧结,能够促进晶粒生长。试样的气孔率和抗弯强度均随着V_2O_5添加量的增加而不断下降。添加0.5%V_2O_5后,低温条件下烧制所得样品的平均气孔率和抗弯强度与相同条件下制备的无添加剂样品的平均气孔率相近。高温条件下延长烧结时间能够降低样品的平均气孔率,但陶瓷基体内会因为部分晶粒的异常生长导致惰性阳极力学性能的弱化。

Effect of V2O5 on Microstructure and Performance of NiFe2O4-based Inert Anodes under Different Sintering Conditions

V2O5-doped NiFe2O4 spinel material was prepared by two-step cold pressing-sintering process. The effect of V2O5 additives on microstructure and performance of NiFe2O4 spinel was studied under different sintering conditions. The results show that eutectic Ni2FeVO6 is generated after introduction of V2O5 into NiFe2O4 ceramic matrix, resulting in liquid-state sintering and promoting grain growth. Porosity and bending strength of sintered samples drop with increase of V2O5 additive amount. With adding 0.5%V2O5, value of average porosity and bending strength for samples sintered at low temperatures are close to those of un-doped samples under the same preparation condition. Prolonging sintering time in high temperature can reduce average porosity, but abnormal grain growth in ceramic matrix will result in weakening mechanical property of inert anodes.