Foam-gelcasting-freeze drying method is developed to fabricate porous Y₂SiO₅ ceramic with ultrahigh porosity of 92.2%-95.8% and isotropous multiple pore structures. As prepared porous samples have quite low shrinkages of 0.8%-1.9% during demolding and drying processes, lightweights of 0.19-0.35 g/cm³, and extremely low thermal conductivities of 0.054-0.089 W·(m·K)⁻¹. Our approach combines the merits of foam-gelcasting method and freeze drying method. It is a simple and effective method to fabricate porous ceramics with very high porosity and extremely low thermal conductivity through low shrinkage of green body and near net complex shape forming.

中文翻译：

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泡沫-凝胶-冷冻干燥法制得的导热率极低的高多孔Y2SiO5陶瓷

研制了泡沫凝胶冷冻干燥方法，制备了孔隙率高达92.2％-95.8％，各向同性的多孔结构的Y ₂ SiO ₅多孔陶瓷。制备的多孔样品在脱模和干燥过程中具有0.8％-1.9％的极低收缩率，0.19-0.35 g / cm ^3的轻量级和0.054-0.089 W·（m·K）^-1的极低热导率。我们的方法结合了泡沫凝胶法和冷冻干燥法的优点。通过生坯的低收缩和接近净复杂形状的形成来制造具有非常高的孔隙率和极低的热导率的多孔陶瓷是一种简单有效的方法。