Comparative experiments were conducted to reveal the removal behaviors of three kinds of silicon carbide(SIC)ceramics during polishing and the effects of ceramic microstructure on the surface quality were also reporte...Comparative experiments were conducted to reveal the removal behaviors of three kinds of silicon carbide(SIC)ceramics during polishing and the effects of ceramic microstructure on the surface quality were also reported.Experimental results show that the second phase in SiC ceramics plays an important role in the surface quality when its size is large enough.The surface quality is enslaved to the formation of steps at interfaces between second phase and SiC matrix that results from different elastic modulus and hardness between two phases.Under 3μm abrasive grains polishing condition,different SiC ceramics show different removal mechanisms.With decreasing abrasive grain size,all of different SiC ceramics exhibit a ductile removal mode,which decreases surface roughness efficiently.展开更多
The effect of density and surface roughness on the optical properties of silicon carbide optical components is investigated. The density is the major factor of the total reflectance while the surface roughness is the ...The effect of density and surface roughness on the optical properties of silicon carbide optical components is investigated. The density is the major factor of the total reflectance while the surface roughness is the major factor of the diffuse reflectance. The specular reflectance of silicon carbide optical components can be improved by increasing the density and decreasing the surface roughness, in the form of reducing bulk absorption and surface-related scattering, respectively. The contribution of the surface roughness to the specular reflectance is much greater than that of the density. When the rms surface roughness decreases to 2.228nm, the specular reflectance decreases to less than 0. 7% accordingly.展开更多
基金supported by the Chinese National Defense Basic Research Projectthe Innovation Project of Shanghai Institute of Ceramics,Chinese Academy of Sciences
文摘Comparative experiments were conducted to reveal the removal behaviors of three kinds of silicon carbide(SIC)ceramics during polishing and the effects of ceramic microstructure on the surface quality were also reported.Experimental results show that the second phase in SiC ceramics plays an important role in the surface quality when its size is large enough.The surface quality is enslaved to the formation of steps at interfaces between second phase and SiC matrix that results from different elastic modulus and hardness between two phases.Under 3μm abrasive grains polishing condition,different SiC ceramics show different removal mechanisms.With decreasing abrasive grain size,all of different SiC ceramics exhibit a ductile removal mode,which decreases surface roughness efficiently.
文摘The effect of density and surface roughness on the optical properties of silicon carbide optical components is investigated. The density is the major factor of the total reflectance while the surface roughness is the major factor of the diffuse reflectance. The specular reflectance of silicon carbide optical components can be improved by increasing the density and decreasing the surface roughness, in the form of reducing bulk absorption and surface-related scattering, respectively. The contribution of the surface roughness to the specular reflectance is much greater than that of the density. When the rms surface roughness decreases to 2.228nm, the specular reflectance decreases to less than 0. 7% accordingly.
