Ceramics International | 2019
Thermal conductivities of MgO–Al2O3 hollow fibers formed by biomimetic synthesis
Abstract
abstract MgO–Al2O3 hollow fibers were effectively prepared by bionics using cogon as a low-cost natural template. Through orthogonal experimental design, the preparation parameters were optimized as follows: Al2O3: MgO ratio of 0.60, mass ratio of 25% solute in the mixture, drying temperature of 80\u202f°C, and sintering temperature of 1100\u202f°C. Overall, with inner pore sizes ranging from 5\u202fμm to 10\u202fμm, the MgO–Al2O3 hollow fibers are a novel low-cost lightweight refractory material. Their stack density is approximately 0.120\u202fg\u202fcm−3 and thermal conductivity is 0.2050 W\u202fm−1\u202fK−1\u202fat 1273\u202fK. In addition, the porosity and average pore area of the hollow fibers are 80.9% and 0.96\u202fm2\u202fg−1, respectively. Here, the effects of pore size, average pore area, and phase composition on the thermal conductivity of the MgO–Al2O3 hollow fibers are discussed synthetically.