透明陶瓷透光性能的影响因素

Influencing factors of transmittance of laser transparent ceramics

研究了影响激光透明陶瓷透光性能的主要因素,讨论了陶瓷内部气孔和杂质颗粒等散射粒子、晶界结构中晶界折射率与晶粒折射率的差异以及晶界表面粗糙度等因素对陶瓷透光性能的影响,并定量分析了激光陶瓷透过率随气孔尺寸、气孔率、晶粒相对晶界折射率以及晶界表面粗糙度的变化关系。结果表明:陶瓷的透过率随着气孔率的减小而增大,但透过率随气孔尺寸的增大而呈现出周期性振荡,且当气孔尺寸与入射光波长可比拟时,陶瓷的透过率会明显降低;在晶界结构中,晶界的折射率与晶粒的折射率相差越小,陶瓷的透过率就越高;晶界表面粗糙度越大,透过率越低。然而,晶界折射率不同于晶粒折射率,这使得其陶瓷透过率降低的程度比对晶界表面粗糙度的影响明显得多。在陶瓷制备过程中,需要重点排除尺寸与入射波长可比拟的气孔,以抑制晶界结构中第二相的产生。

The main factors affecting the transmittance of laser transparent ceramics are studied.The effects of the scattering particles including inner pores and impurity particles,the difference of refractive index between the boundary and the grain in the boundary structure,as well as the boundary surface roughness on the transmittance of laser transparent ceramics are discussed.Moreover,the variation of the transmittance with pore size,porosity,relative refractive index of grain to boundary,and the surface roughness are analyzed quantitatively.The results indicate that the transmittance of the laser ceramics increases with the decreasing of porosity.The transmittance oscillates periodically with the increase of the pore size,and decreases obviously when the pore size and the wavelength of the incident light are close to each other.Furthermore,the transmittance increases as the relative refractive index between boundary and grain,and the roughness of the boundary decrease,and the effect of the relative refractive index is more obvious.Consequently,in the fabrication of ceramics,more attention should be paid to the control of the porosity,pore size and precipitates of boundary structure.