Preparation and properties of low-emissivity infrared Y2O3-MgO nanocomposite ceramics

YM nanocomposite ceramics, featuring high transmittance and low emissivity in the 3-5 μm range, is considered a promising candidate for infrared window applications. Powder synthesis and ceramic sintering are currently key areas of research. In this study, a glycine-nitrate combustion method combined with air pre-sintering and hot isostatic pressing was employed to successfully prepare nanopowders with an average grain size of ∼20 nm and dense nanocomposite ceramics with an average grain size of ∼170 nm. This method allows for the fabrication of samples with various sizes and shapes. The effects of glycine as fuel on powder and ceramic properties were investigated. At a glycine-to-nitrate ratio (N/G) of 0.7, the YM ceramics exhibited a transmittance above 80% and an emissivity approach 2% at 600 °C in the 3-5 μm range. Besides, for the first time, the differences and influencing factors in emissivity were comparatively analyzed. The ceramic also demonstrated a flexural strength of 300-500 MPa at room temperature. Finally, the transmittance, emissivity, and imaging performance of the YM composite ceramics were systematically compared with those of conventional infrared window materials. These findings are rarely reported and provide a valuable reference for future research and application of infrared window materials.