Hot-pressed Transparent β-Si_3N_4 Ceramic

The transparent β-Si3N4 ceramic was prepared by hot-pressing at 2 000 ℃ for 26 h,with MgSiN2 as additives.The result of XRD showed that the ceramic was composed of pure β-Si3N4.The transmittance of the transparent β-Si3N4 ceramic gradually increased with the increase of wavelength and achieved the maximum transmittance of 70% at the wavelength of about 2.5 μm.The transmittance value keeps higher than 60% in the range of 0.7-4.0 μm wavelength and the cut-off wavelength of this β-Si3N4ceramic is located at 5.0 μm.