ELECTRON-PROBE MICROANALYSIS OF NICALON FIBERS

Electron probe microanalysis of a sample of Nicalon fibre showed it to consist of 54.9 wt% Si, 32.1 wt% C and 11.6 wt% 0. Studies of the fine structure of the X-ray emission bands suggested these elements were combined as 46 vol % silicon carbide, 34 vol % silicon oxycarbide and 20 vol % free carbon, with the oxycarbide in the outermost regions of the fibre being significantly richer in oxygen. The silicon carbide was composed of microcrystallites several micrometres in diameter and the remaining material formed an amorphous network of material surrounding the microcrystallites.