Fabrication of Highly Transparentγ-AlON Ceramics from High Sinterability Powders by Using Spark Plasma Sintering Method and Hot Isostatic Pressing Post-treatment

摘要

Highly-transparent γ-AlON ceramics were fabricated with using γ-AlON powders synthesized from Al_2O_3 and AlN, and prepared MgAl_2O_4 as raw materials by spark plasma sintering (SPS) technique at 1800 ℃ for 5 min under 80 MPa pressure assisted with post-treatment of hot isostatic pressing (HIP) at 1800 ℃ for 2 h under 190 MPa pressure. The sintered transparent ceramic fabricated by the prepared γ-AlON powders with using MgAl_2O_4 as additive demonstrated almost even grains and no pores either at the grain boundaries or inside the grains, with a high in-line transmittance efficiency in the region of UV~visible wavelength, as high as～80.5%at 450 nm wavelength (Figure 1), which is attributed to a contribution of the MgAl_2O_4 additive in efficiently promoting the sinterability ofγ-AlON powders and finally resulting in the high densification ofγ-AlON transparent ceramic.