Load Induced X-Ray Line Broadening in Nylon Filaments

Abstract

The load induced microscopic structural changes in highly oriented Nylon filaments were followed by changes in the x‐ray fiber diffraction pattern as a function of the resulting strain. Observations made included (1) changes in the dimensions of the fiber spots, and (2) a decrease in ratio of the intensity of amorphous to crystalline x‐ray scattering. These new results for Type 200 du Pont Nylon indicate a change in the micro deformation mechanism at a strain corresponding to the inflection of the load‐strain diagram (14 percent elongation). The mechanism for smaller plastic strains appears to involve a rotation of the crystallized domains into alignment with the fiber axis, accompanied by a small over‐all additional crystallization. For strains larger than the inflectional strain, the mechanism seems to involve a progressive reduction in the domain size, and a reduction in alignment with the fiber axis. Both effects appear to saturate in the vicinity of the rupture strain. These results are discussed in terms of load induced effects found in metal single and polycrystals. It is suggested that the qualitative features observed may be representative of a wide class of load or strain induced micro deformation reactions in the solid state.