２母数Ｗｅｉｂｕｌｌ統計モデルを用いたＴｙｒａｎｎｏ ＺＭＩ繊維強度評価―繊維直径および内部欠陥の各母数への影響―

Abstract

Tyranno ZMI Si-Zr-C-O fiber has been assessed if a set of parameters for single-modal Weibull model accurately scales the tensile strength of different diameter samples. Tyranno ZMI fiber has been known to have different diameters for both along the gauge length and between individual fibers within a bundle. Although Tyranno ZMI is an amorphous fiber, localized crystallization in a large diameter section may bias the strength from the Weibull scaling. In addition, large diameter sections may contain contaminant particles in different probability from small diameter sections and the particles probably disturb the spinning process. Thus, the parameters of single-modal Weibull model may vary as functions of fiber diameter. The strength estimation may be thus more reliable by correlating the factors of fiber diameter. What is more, key information for improving the reliability may be derived through coupling the Weibull strength scaling on different sets of fiber diameter samples and the fracture surface analyses. The authors thus assess in this study if the parameters of single-modal Weibull model vary with the sample diameters. The data of single fiber tensile tests had been divided into two groups, “small diameter” group and “large diameter group.” The Weibull parameters of the two groups showed inconsistency each other, and scanning electron microscope (SEM) analyses had revealed characteristic fractographs to one group. Thus, the authors have concluded that the parameters of single-modal Weibull model are dependent on the sample diameter on the strength scaling of Tyranno ZMI fiber.