F- Chen et aL/ Engineering Failure Analysis 37(2014)29-41 a 20um e:edax32genesis'genmaps, spe 01-Jul-2011 18: 28: 5 eLa 1.002003.00400 7008009.0 merry.ke Fig 9. Composition analysis of the wear zone on tube1B134027-1(a) strp deposit(b)EDS analysis of the strip deposit. EDS results of the strip deposit. WE6 29.34 3.2. Failure analysis of titanium tube 1B160012-14 3. 2. 1. Visual inspection Fig. 10 is the exterior appearance of titanium tube 1B160012-14. The wear zone is mainly distributed from 0 to 1700 (Fig. 10(a and b)), but there are no obvious wear traces in the backward direction (Fig. 10(c and d)). the wear zone in the forward direction looks shiny and smooth and is not abraded seriously. But a visible S-shaped furrow crack is found in the wear zone(Fig. 10(e)), which is about 7 mm long parallel to the longitudinal direction and 10 mm long in the circum- ferential direction 3. 2. Microscopic To further observe the morphology characteristics of the furrow crack, 3-D stereo microscope was applied to image the surface wear zone of the tube, shown in Fig. 11. From Fig. 11(a)we can learn that the furrow crack is obviously deeper than3.2. Failure analysis of titanium tube 1B160012-14 3.2.1. Visual inspection Fig. 10 is the exterior appearance of titanium tube 1B160012-14. The wear zone is mainly distributed from 0 to 170 (Fig. 10(a and b)), but there are no obvious wear traces in the backward direction (Fig. 10(c and d)). The wear zone in the forward direction looks shiny and smooth and is not abraded seriously. But a visible S-shaped furrow crack is found in the wear zone (Fig. 10(e)), which is about 7 mm long parallel to the longitudinal direction and 10 mm long in the circum￾ferential direction. 3.2.2. Microscopic observation by 3-D stereo microscope To further observe the morphology characteristics of the furrow crack, 3-D stereo microscope was applied to image the surface wear zone of the tube, shown in Fig. 11. From Fig. 11(a) we can learn that the furrow crack is obviously deeper than Fig. 9. Composition analysis of the wear zone on tube1B134027-1 (a) strip deposit (b) EDS analysis of the strip deposit. Table 2 EDS results of the strip deposit. Element O Ti Fe Wt% 29.34 3.56 67.10 F.-J. Chen et al. / Engineering Failure Analysis 37 (2014) 29–41 35