Abstract:

Viscose fiber templates (15 cm×15 cm×1 cm) were put into ZrOCl₂ solutions of different concentrations (1,2 and 3 mol·L^-1) and impregnated at 20,40 and 60 ℃ for 20 h,respectively.After washing,centrifugation and drying,ZrO₂ fiber precursors were obtained.ZrO₂ fibers were prepared by heat treatment of the precursors at 600,800,1 000 and 1 200 ℃ for 2 h.The effects of the impregnation temperature,the impregnation solution concentrations and the heat treatment temperature on the microstructure and the phase composition of the ZrO₂ fibers were studied.The results show that with the increase of the impregnation temperature from 20 ℃ to 60 ℃ and the impregnation solution concentration increases from 1 mol·L^-1 to 3 mol·L^-1,the microstructure of fiber cross section changes from flat to cylindrical,and the average fiber diameter increases,indicating that the increase of the impregnation solution concentration and the impregnation temperature is beneficial to increasing the adsorption capacity of Zr⁴⁺ on viscose fiber templates.After heat treatment,ZrO₂ fiber mainly exists in monoclinic ZrO₂ phase.With the increase of the heat treatment temperature,the grains in ZrO₂ fibers become larger and the crystallinity degree increases,meanwhile the fiber surface undergoes a transition from smooth to small grains and then to cracks.

Key words: zirconia fiber, template impregnation method, micro-morphology, diameter

摘要：

将15 cm×15 cm×1 cm的粘胶纤维模板放入浓度为1、2及3 mol·L^-1的ZrOCl₂溶液,分别在20、40、60 ℃下浸渍20 h,经过洗涤、离心、干燥得到ZrO₂纤维前驱体,再对前驱体进行600、800、1 000、1 200 ℃保温 2 h热处理制得ZrO₂纤维。研究浸渍温度、浸渍液浓度、热处理温度对ZrO₂纤维形貌和相组成的影响。结果表明,随着浸渍温度由20 ℃提高到60 ℃,浸渍液浓度由1 mol·L^-1提高到3 mol·L^-1,纤维横截面微观形貌由扁平状向圆柱状变化,同时纤维的平均直径逐渐增大,说明提高浸渍温度和浸渍液浓度有利于粘胶纤维模板对Zr⁴⁺的吸附。ZrO₂纤维经过热处理后,主要是以单斜相ZrO₂存在。随着热处理温度的增加,ZrO₂纤维晶粒变大,结晶程度增加,同时纤维表面经历由光滑到小晶粒出现再到裂纹出现的转变。

关键词: ZrO₂纤维, 模板浸渍法, 显微形貌, 直径