Highly Transparent Lu‐α‐SiAlON

Novel Lu-α-SiAlON ceramics were produced by hot pressing mixtures of Si3N4, Lu2O3, AlN, and Al2O3 at 1950°C for 2 h in a nitrogen atmosphere. The resultant SiAlON was fully dense and possessed a uniform, equiaxed microstructure with a grain size of ∼1 μm, which resulted in a high hardness of >19 GPa. In addition to high hardness, the sample showed very high optical transparency in the visible light region, with >70% transmission at higher wavelengths. This high transparency was attributed to the uniform, dense microstructure and lack of residual grain-boundary phase.

[1]  Y. Kagawa,et al.  Effect of grain boundary microcracking on the light transmittance of sintered transparent MgAl2O4 , 2003 .

[2]  K. Hirao,et al.  Optical and Mechanical Properties of a/ Composite Sialons , 2003 .

[3]  Rolf Apetz,et al.  Transparent Alumina: A Light‐Scattering Model , 2003 .

[4]  S. Guo,et al.  Strength Retention in Hot-Pressed Si3N4 Ceramics with Lu2O3 Additives after Oxidation Exposure in Air at 1500°C , 2002 .

[5]  Htjm Bert Hintzen,et al.  Luminescence Properties of Terbium-, Cerium-, or Europium-Doped α-Sialon Materials , 2002 .

[6]  S. Guo,et al.  Improvement of high-temperature strength of hot-pressed sintering silicon nitride with Lu2O3 addition , 2001 .

[7]  R. Roy,et al.  Microwave reactive sintering to fully transparent aluminum oxynitride (ALON) ceramics , 2001 .

[8]  L. A. Genova,et al.  Progress in SiAlON ceramics , 2000 .

[9]  Hasan Mandal,et al.  New developments in a-SiAlON ceramics , 1999 .

[10]  M. Nygren,et al.  On the extension of the α-sialon phase area in yttrium and rare-earth doped systems , 1997 .

[11]  M. Nygren,et al.  Reactions occurring in post heat-treated αβ sialons: On the thermal stability of α-sialon , 1996 .

[12]  M. Sakamoto,et al.  Oxidation Behavior of RE-α-Sialon Ceramics (RE=Nd, Sm, Gd, Dy, Y, Ho, Er, Yb) , 1993 .

[13]  M. Mitomo,et al.  Translucent β-sialon ceramics , 1982 .

[14]  R Ruud Metselaar,et al.  Light scattering by pores in polycrystalline materials: Transmission properties of alumina , 1974 .