中文摘要：

以高纯氧化物粉体为原料,采用直接干压成型与固相反应烧结技术制备Nd：YAG透明陶瓷,并对其光学透过率和烧结致密化行为进行了研究。结果表明,经1 760℃烧结10 h后,250 MPa成型压力下的样品透过率最高,在1 064 nm处达到83.8%。其素坯的气孔率为40.5%,气孔平均孔径74.5 nm。烧结后陶瓷的显微结构致密,晶界干净清晰,断裂方式为沿晶断裂。将250 MPa成型压力下获得的陶瓷素坯在不同温度和时间下烧结,得到致密化轨迹、晶粒生长曲线以及显微结构演变等信息。通过理论拟合,得出低温下陶瓷致密化和晶粒生长的控制机制为晶界扩散。

英文摘要：

Nd：YAG transparent ceramics were fabricated by direct dry pressing and solid reactive sintering with high-purity oxide powders as starting materials. The optical transmittance and sintering behavior of Nd：YAG ceramics were investigated. The results show that the Nd：YAG ceramics sintered at 1 760℃ for 10 h from the 250 MPa dry pressed green body reaches the maximum transmittance value of 83.8% at 1 064 nm. The porosity of this green body is 40.5%, and the average pore size diameter is 74.5 nm. The sintered Nd：YAG ceramics have a dense microstructure and a clear grain boundary with the mode of intergranular fracture. The green bodies dry-pressed at 250 MPa were sintered from 1 500 to 1 750 ℃ for 0.5-20.0 h to analyze their densification trajectories, grain growth and microstructure evolution. The control mechanism of the densification and grain growth at 1 550 ℃ is grain boundary diffusion.