Engineering directional pore structures in YSZ ceramics for superior infrared reflectance

High-temperature infrared-regulating ceramics are essential for extreme-environment applications requiring broadband infrared reflection (1–6 μm), such as spacecraft thermal protection, military stealth systems, and related fields. Precise control of pore structures is crucial for enhancing ceramic infrared reflectance, as pores directly influence the scattering intensity and scattering path of radiation. However, achieving broadband reflectance above 0.9 remains challenging because of unclear pore‒radiation interaction mechanisms and insufficient structural control. This study employs optical simulations to systematically analyze how pore parameters enhance infrared reflectance. The results demonstrate that pore sizes matching the infrared wavelength, high aspect ratios, and aligned orientations synergistically enhance reflection. Guided by simulations, directional pore-structured yttria-stabilized zirconia (YSZ) ceramics were fabricated via a rolling extrusion method using graphite flakes as sacrificial templates. The optimized ceramics exhibited tailored pore parameters (size: 0.2–6 μm, aspect ratio: 3.2–3.9, orientation angle: < 30°), achieving exceptional infrared reflectance (> 0.9). This study clarifies pore‒radiation interactions and presents a scalable strategy to produce advanced thermal shielding materials.