13th International Conference on Fracture June 16–21, 2013, Beijing, China -5- (a) Unusual color (b) Microscopic character (c) Variation trend of grain size Figure. 6 Plane shaped fracture of bad welding 3.3. Inclined shaped fracture The fracture surface of inclined shaped was an angle to wire drawing direction, and crack, little hole or other defects would be found nearby fracture. Different wire surface defects corresponded to fracture cause which included scratching, abrasions, die broken, poor lubrication, etc [8]. Morphology of inclined shaped facture and a typical surface defect was showed in Fig. 7 and Fig. 8, respectively. Microscopic analysis of inclined shaped fracture was brittle fracture feature, shown in Fig. 9. Trend of surface crack and poor deformability microstructure would be observed by longitudinal metallographic examination, shown in Fig. 10. Microscopic analysis and metallographic examination procedure of inclined shaped fracture should be: (1) Wire surface of fracture should be examined to find defect of crack, scratches and so on. (2) SEM would be used to identify microstructural character and defect mode. (3) Longitudinal metallurgical examination would be used to observe trend of crack and poor deformability. Figure. 7 Morphology of inclined shaped facture
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