MgO对快速烧结制备氧化铝透明陶瓷光学性能的影响

Effect of MgO on Optical Property of Alumina Transparent Ceramics Prepared by Rapid Sintering

采用真空快速烧结制备氧化铝透明陶瓷,研究了添加剂MgO对氧化铝透明陶瓷烧结致密化及透光性能的影响。研究表明,添加剂MgO以富Mg的纳米颗粒在晶界区的钉扎作用有效地抑制了晶粒长大,同时短时烧结在动力学上也抑制了晶粒的长大。通过对材料透光性能的分析,基于Rayleigh-Gans-Debye光散射模型提出了理论气孔率Pt、等效气孔率Pe的概念,用以定量分析添加剂MgO对多晶氧化铝透明陶瓷透光性能的影响。拟合结果显示等效气孔率Pe与MgO添加量满足二次多项式函数关系。当MgO添加量为0. 075wt%时,理论气孔率最低,等效气孔率适中,透光性能最好。

Transparent alumina ceramics were prepared by rapid vacuum sintering. The effect of MgO additive on sintering densification and light transmittance of transparent alumina ceramics was studied. The results show that the grain growth is effectively inhibited by the pinning effect of MgO-rich nanoparticles in the grain boundary region,and the grain growth is also inhibited by short-term sintering kinetics. Based on the Rayleigh-Gans-Debye light scattering model,the concepts of theoretical porosity Ptand equivalent porosity Peare proposed to quantitatively analyze the effect of MgO additive on the light transmission performance of PCA. The fitting results show that the equivalent porosity Peand MgO content satisfy the quadratic function relationship. When the MgO content is 0. 075 wt%,the theoretical porosity is the lowest,the equivalent porosity is moderate,and the light transmittance is the best.