Fabrication of AION transparent ceramics with Si_(3)N_(4) sintering additive

In this paper,Si_(3)N_(4) was used as a novel solid-state sintering additive to prepare AION transparent ceramics with high transparency and flexural strength via the pressureless pre-sintering and hot isostatic pressing(HIP)method at a relatively low HIP temperature(1800℃).The effect of Si_(3)N_(4) content on the phase,microstructure,optical property,and flexural strength was investigated.The experimental results showed that a Si element was homogenously distributed in both pre-sintered and HIPed AION ceramics.The densification enhanced,the grain grew with the increasing Si_(3)N_(4) content in the pre-sintered AION ceramics,and all the samples became pore-free after HIP,which favor transparency.The AION ceramics doped with 0.10 wt%Si_(3)N_(4) had the highest transmittance of 83.8%at 600 nm and 85.6%at 2000 nm(4 mm in thickness),with flexural strength of 404 MPa,which were higher than those of the previous reports.