Effect of sintering parameters on microstructure and properties of transparent AlON ceramics via tape casting
Year: 2026
Type: article
Abstract: Transparent aluminum oxynitride (AlON) ceramics are promising materials for optical windows and substrates for laser transmission, optical storage, photodetection, and wave-transparent electronic applications because of their high transparency, mechanical robustness, thermal stability, and stable dielectric response. Nevertheless, scalable fabrication of transparent AlON sheets remains challenging because it requires the formation of defect-free green bodies and the elimination of residual pores during sintering. In this work, high-purity AlON powder prepared by carbothermal reduction and nitridation was processed into green tapes through a nonaqueous tape-casting route, followed by hot-press lamination and pressureless sintering. The effects of slurry formulation, lamination parameters, and especially the sintering holding time at [Formula: see text]C on microstructure and properties were systematically examined. Prolonging the holding time promoted densification, grain development, pore elimination, and a corresponding increase in in-line transmittance, residual pores are mainly light-scattering centers in transparent ceramics, rather than intrinsic absorption sites. At the optimized holding time, 2 mm-thick AlON ceramics showed a maximum in-line transmittance of 80.2% over the 200–1400[Formula: see text]nm range, a bending strength of 343 MPa, and a Vickers hardness of 18.5 GPa. The relative density increased to approximately 99.8% of the theoretical value, and the dielectric constant approached the intrinsic value expected of dense AlON. The results provide a practical processing basis for preparing transparent AlON ceramic sheets, while further optimization is still required for reliable fabrication of larger-area substrates.
Source: Journal of Advanced Dielectrics
Authors: Zhenzhu Kong, Lin Han, Yuanlin Li, Xiangzhao Meng, Bin Peng, Yanan Zhao
Institution: Xi'an Jiaotong University
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
Awards: G5886557581, G8953049015
OpenAlex ID: W7165889382