摘要
通过TG／DSC和高温XRD对石英纤维的高温相转变行为进行了研究，通过高分辨SEM对经不同温度处理过的石英纤维的表面形貌进行了研究，并用抗拉强度实验机测量了这些石英纤维的抗拉强度。研究结果表明，低于1000℃处理的石英纤维热损伤可分为两个阶段：（1）在低于600℃的热处理温度范围内，由于石英纤维表面处理剂的挥发，石英纤维直径逐渐减小，原来表面的裂纹、条状和圆形凸起等缺陷逐渐显露出来，导致石英纤维抗拉强度缓慢降低；（2）在600～1000℃的热处理温度范围内，石英纤维表面处理剂挥发完毕，在热处理的升降温过程中，由于热应力的作用，表面的条状和圆形凸起开始剥落，造成一定数量的新的表面裂口和裂纹缺陷。温度越高，石英纤维表面的条状和圆形凸起剥落现象越明显，这是造成这一温度条件下石英纤维强度显著降低的主要因素之一。此外，结合TG／DSC和XRD的研究结果，石英纤维低于1000℃热处理后，虽然没有明显的相变化，但是晶体结构有序化程度提高，表面开始析出α-方石英并导致纤维表面形成一定数量的凸起缺陷，这也是导致高温处理后石英纤维热损伤的原因之一。
In this paper, TG/DSC and high temperature XRD were engaged in studying phase transformation behavior of quartz fibers, high resolution SEM was engaged in studying surface micromorphology of heat treated quartz fibers at different temperatures, and the tensile strength of these quartz fibers was measured by a tensile- strength tester. The results indicate that thermal damage of quartz fibers under 1000℃ has two stages： （1） with heat treatment under 600℃, the tensile strength decreases slowly with increasing temperature because diameters of quartz fibers decrease and the original cracks, strip and round bulges on the surface are exposed after surface finishing agent volatilized; （2） with heat treatment at 600 ～1000℃, thermal stress caused those bulges to flake off and formed some new rifts and cracks. The higher heat treatment temperature is, the more rifts and cracks occur. This is one of the important factors that decreases tensile strength markedly. The results on quartz fiber by TG/DSC and XRD show that though no obvious crystallization occurs, the crystal structure ordering increases after heat treatment under 1000＊C and a little α-cristobalite occurs on the surface causing new bulge defects. This is also another one of the important factors resulting in thermal damage of quartz fibers.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2008年第1期105-111,共7页
Acta Materiae Compositae Sinica
基金
中国人民解放军总装备部武器装备预研基金项目(2005JS51469.0201.QT06.1)
关键词
石英纤维
晶化
抗拉强度
微观结构
quartz fiber
crystallization
tensile strength
microstructure
