In this work, a systematic research is carried out to investigate the sintering kinetics of NiFe₂O₄ ceramic obtained by slip casting and pressureless sintering. The sintering shrinkage behaviors showed the linear shrinkage and linear shrinkage rate of the green body in the axial and radial directions, both increased with increasing sintering temperature, though the maximum linear shrinkage rate in the radial direction was acquired at a lower temperature (1280.7°C) than that in the axial direction (1305.4°C) for a denser compact. The temperature related to the maximum densification rate was about 1316.5°C while the relative density was around 72%. The characteristic sintering kinetics window exhibited that the sintering process could be typically divided into three stages. The sintering activation energy of the initial stage was 268.34 kJ mol⁻¹, and the initial stage of the sintering process was controlled by both grain boundary diffusion and volume diffusion mechanisms. The grain growth kinetic analysis illustrated the grain growth exponent (n) reduced from 2.959 to 2.169 when the sintering temperature increased from 1300 to 1375°C, while the activation energy for grain growth decreased with both the increasing of sintering temperature and the shortening of holding time. It implied that the atomic diffusion process controlled the grain growth. In addition, it was observed that increases in the bending strength and elastic modulus reached its maximum value of 70.36 ± 1.03 MPa and 3.44 ± 0.53 GPa, respectively, mainly associated with the relatively dense microstructure.

在这项工作中，进行了系统的研究，以研究NiFe ₂ O ₄的烧结动力学通过压铸和无压烧结获得的陶瓷。烧结收缩行为表明生坯在轴向和径向上的线性收缩率和线性收缩率均随烧结温度的升高而增加，尽管在较低温度（1280.7°C）下获得了径向上的最大线性收缩率）比轴向（1305.4°C）的密度高。与最大致密化速率有关的温度为约1316.5℃，而相对密度为约72％。典型的烧结动力学窗口表明，烧结过程通常可以分为三个阶段。初始阶段的烧结活化能为268.34 kJ mol ^-1，并且烧结过程的初始阶段受晶界扩散和体积扩散机制的控制。晶粒长大动力学分析表明，当烧结温度从1300升高到1375°C时，晶粒长大指数（n）从2.959降低到2.169，而随着烧结温度的升高和保温时间的缩短，晶粒长大的活化能降低。时间。这表明原子扩散过程控制了晶粒的生长。另外，观察到弯曲强度和弹性模量的增加分别达到其最大值70.36±1.03MPa和3.44±0.53GPa，这主要与相对致密的微观结构有关。