Comparative analyses of the influence of tetraethoxysilane additives on the sintering kinetics of Nd:YAG transparent ceramics

In this work, the sintering kinetics of Nd:YAG transparent ceramics under the vacuum environment were investigated by the high-temperature solid-state reaction. We focus on the influence of tetraethoxysilane (TEOS) content on the densification process of Nd:YAG ceramics. Meanwhile, the crystal structure of Nd:YAG transparent ceramics doped with different contents of TEOS was studied by X-ray diffractometer (XRD) and differential thermal analysis (DTA). The micrographs of ceramic samples were analyzed by scanning electron microscope (SEM). The green sample is heated to 1450–1650 °C for 0–2 h at a heating rate of 20 °C/min in a vacuum environment (PT ≤ 10−6 Pa), and the shrinkage of ceramic samples was analyzed in the vacuum atmosphere by the Johnson sintering model. The sintering activation energy of Nd:YAG transparent ceramics doped with different contents of TEOS was obtained. The results indicated that the addition of TEOS promoted the densification of ceramic samples. The grain size and relative density of ceramic samples increased, and the sintering activation energy decreased with the increase of TEOS content.