Effects of Impurities and Manufacturing Methods on the Devitrification of Silica Fibers

Devitrification resistance is one of the most important properties of silica fibers. The devitrification behavior of silica fibers made by the acid leaching method, the sol‐gel method, and the high‐purity silica fusing method, and the effects of small amounts of Al₂O₃ and B₂O₃, were studied by using X‐ray diffraction. The results indicated that the devitrification tendency of silica fibers made by the high‐purity silica fusing method is apparently greater than that of the fibers made by the other two methods. A small amount of B₂O₃ has the effect of retarding devitrification, while Al₂O₃ promotes devitrification of the fibers. The combined effect of Al₂O₃ and B₂O₃ is to strongly enhance the devitrification of silica fibers. The results are discussed in the context of structural analysis.