Abstract: To study the effect of the particle size and the reaction temperature of SiO₂ raw material on the synthesis of mullite whiskers by the molten salt method,mullite whisker samples were synthesized using Al₂(SO₄)₃·18H₂O and SiO₂ (d₅₀=80.25,45.16,0.91,and 0.02 μm,respectively) as starting materials,and Na₂SO₄ as the molten salt media,firing at 800,900,1 000,and 1 100 ℃ for 3 h,respectively,soaking in distilled water,sucking filtering,washing,and drying.The phase composition and the microstructure of the samples were analyzed.The results show that the optimal preparation conditions are adopting SiO₂ of d₅₀=0.02 μm and firing at 900 ℃.The obtained mullite whisker performs good crystallization,high purity and large length-diameter ratios.

Key words: mullite whisker, molten salt method, silica, particle size, reaction temperature, phase composition

摘要： 为了研究SiO₂原料粒度和反应温度对熔盐法合成莫来石晶须的影响,以Al₂(SO₄)₃·18H₂O和d₅₀分别为80.25、45.16、0.91、0.02 μm的SiO₂为原料,以Na₂SO₄为熔盐介质,分别在800、900、1 000、1 100 ℃保温3 h后,经蒸馏水浸泡、抽滤、洗涤、烘干制成莫来石晶须试样,分析了莫来石晶须试样的物相组成和显微结构。结果表明:最佳制备条件为采用d₅₀=0.02 μm的SiO₂,制备温度为900 ℃;所制备的莫来石晶须结晶良好,纯度较高,长径比较大。

关键词: 莫来石晶须, 熔盐法, 二氧化硅, 粒度, 反应温度, 物相组成