Electron micrographs, deformation tests

Electron Microscopic Results. Electron micrographs were obtained from deformation tests of toughened PP and PA. The micrographs of toughened PP shown in Figure 13 reveal ruptured particles and plastically deformed matrix material between these voids. The cavitation step inside the particles, with the subsequent deformation and fibrillation of the adjacent material, can also be clearly seen in Figure 14. 

Figure 13.14. Scanning electron micrographs of polyurea-crosslinked vanadia (X-VO pt = 0.444 gcm" ) and polyurea-crosslinked silica (X-SiOx, pb = 0.480 g cm ) before and after compression testing at room temperature (23°C). A. Undeformed X-VO - B. Deformed X-VO after compression to 91% strain at strain rate 5 x 10" s" . Some nanoworms are fused after compression. The specimen after compression did not break into smaller pieces, remaining as one piece. C. Undeformed X-SiO - D. The core of a X-SiOx specimen after faUuie at 77% strain (see Figure 13.6).

After completion of the tensile or creep test, the thin flat electropolished samples were examined in an electron microscope [ ]. Figure 1 shows a typical micrograph. The dark bands, a few tenths of a micron in width, appear as the strain increases in the regions where dislocations occur (as shown on preliminary pictures). Further deformation produces platelets of martensite (D). 

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