Tensile fracture surface

Figure 16 SEM of tensile fracture surface of (a) PMPPIC treated and (b) untreated PALF-LDPE composites.

FIGURE 12.11 Scanning electron microscopy (SEM) photomicrographs of the tensile fracture surface of the ethylene-propylene-diene monomer (EPDM) rubber-melamine fiber composites. A, before ageing and B, after ageing at 150°C for 48 h. Test specimen is cut in tbe direction parallel to the milling direction. (From Rajeev, R.S., Bhowmick, A.K., De, S.K., Kao, G.J.P., and Bandyopadhyay, S., Polym. Compos., 23, 574, 2002. With permission.)... 

Figure 5. Scanning electron micrograph of tensile fractured surface of 30% glass reinforced MA-modified PP (unstabi1ised, 1C1-HF22).

The micrographs obtained from scanning electron microscopy are shown in Fig. 54 for the tensile fractured surface of 50 CR/50 XNBR self-crosslinked blend filled with 10 phr layered silicate (Fig. 54a) and for the same blend without any... 

Fig. 54 Scanning electron micrographs of the tensile fractured surface of 50 CR/50 XNBR blends with modified layered silicate (a) and without any filler (b)...

Figure 4. Tensile fracture surfaces for three structural types of high-modulus mesophase carbon fibers (E = 100 Mpsi ...

Figure 6. Tensile fracture surfaces for a mesophase carbon filament with tensile modulus of 120 Mpsi (827 GPa).

Fig. 2a. Typical tensile fracture surface of PS b high magnification of a portion of tensile fracture surface of PS...

Fracture initiated in the tensile tested ABS samples, as noted also by Truss and Chadwick from either surface flaws or from internal flaws. Figure 33a shows an SEM picture of the tensile fracture surface of a sample broken at a comparatively high deformation rate of 12.7 cm/min. The fracture surface is unlike that of SAN (Fig. 27 a) or that of rubber modified polystyrene (Fig. 3 a). Fracture, for this specimen, has developed from both a surface source and from an internal source and fine radial flow lines emanate from both sources. The slow growth region adjacent to the source tends to develop a conical shape as has been noted This is probably a result of localized shear formation. In ABS specimens subject to creep deformation at low values of stress, the creep strain is found to be due almost entirely to shear but, at higher stresses, shear is accompanied by crazing Crazes can also be induced... 

Fig, 33a—c. Tensile fracture surfaces of ABS specimens tested at a displacement rate of 12.7 cm/min a Low magnification scan b Higher magnification near internal source c High magnification near external source... 

Fig. 10a, b. Portions of the tensile fracture surface of PSAN with M = 1.85 x 10 . a Mackeral type region adjacent to the fracture source b High magnification scan of a craze edge... 

The SEM data of the tensile fracture surface of the high rubber blend show a rough surface... 

Figure 15.3 Scanning electron micrographs of tensile fractured surfaces of the vulcanizates cured at 160°C (a) 75 25 unsaturated natural rubber-ethylene-propylene-diene (NR-EPDM) blend (one-stage) at 500 x (b) 75 25 NR-EPDM blend (two-stage) at 500 x (c) 50 50 NR-EPDM blend (one-stage) at 750 x (d) 50 50 NR-EPDM blend (two-stage) at 750 x. (From Reference 32 with permission from John Wiley Sons.)...

The room temperature tensile stress strain behaviors of 1 -D and 2-D SiC/Si3N4 monofilament composites showed high matrix cracking stress, but strain capability beyond matrix fracture is limited. Limited fiber pull out was observed on the tensile fracture surfaces [31]. 

The crack plane in tension remained generally perpendicular to the direction of the applied load, without any deviation into the interlaminar plies. Oxidation of the composites did not change this general trend. SEM was performed on the tensile fracture surfaces to characterize the nature of the tensile failure. Micrographs of the fracture surfaces of the 5X and 8X as-prepared composites show a relatively rough fracture surface, but with very limited fiber pull-out. This corresponds well with the relatively low tensile failure strains of 0.2% seen in both of these composites. 

SEM analysis of the tensile fracture surface for the 5X and 8X bars after the 600°C, 1000-hour, oxidation shows that the fracture surfaces for the oxidized test bars are rougher... 

Polymer nanocomposites were processed using non-treated alumina (NT-Al Oj) and aminopropyltriethoxysilane treated alumina (APTES-Al Oj) in epoxy matrix [97-98]. The tensile fracture surface is evaluated for analyzing the strengthening and toughening mechanisms. The tensile fracture surfaces of neat epoxy and nanocomposites containing 10 phr-NT- Al O and 10 phr-APTES- Al O are shown in Figure 9.34. 

Figure 9.34 Scanning electron micrographs showing the tensile fracture surfaces of (a) neat polymer, (b) 10 phr NT-Al O, nanocomposites, and (c) 10 phr APTES-AI2O3 nanocomposites. A - mirror zone, B - mist zone, C - hackle zone. Reprinted from [97] with permission from Elsevier.

Figure 27.7 SEM tensile fracture surface of untreated (a) and 4% NaOH treated (b) sisal/oil palm reinforced natural rubber composites.

Fig. 11.20 SEM of the tensile fractured surfaces containing (a) untreated fibre without bonding gent and (b) treated fibre with bonding agent of the composites X30 and Y30b...

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