Mechanical degradation of basalt fiber at elevated temperatures (300∼360 °C) studied through semi-quantitative analysis of X-ray photoelectron spectrometry

This work conducted a semi-quantitative analysis of structural variations in the surfaces and interiors of basalt fibers at 300 °C∼360 °C using X-ray photoelectron spectrometry. The proportions of non-bridging oxygen (NBO) of fiber surfaces are significantly higher than those in the interiors, due to the surface oxidation that occurs during the fiber manufacturing process. After heat treatment, the NBO contents of the interiors significantly exceeded those of the surfaces, indicating that the oxidation of the fibers is intrinsic and independent of environmental oxygen. Tensile tests showed that the structural variation of the fiber interior affects the fiber modulus, while that of the surface affects the growth of surface flaws, which manifests as the reduction of breaking elongation. This study presents an analytical method that contributes to a deeper understanding of the mechanisms underlying the mechanical degradation of those basaltic fibers at elevated temperatures.