Flame-sprayed aluminum oxide coating on steel

Flame-sprayed aluminum oxide coating on steel... 

Table 46. Recommended preparation of a flame-sprayed aluminum oxide coating on steel...

Figure 104. Flame-sprayed aluminum oxide coating on steel, DIC. The sample was mounted in epoxy resin before sectioning. Arrows indicate cavities, which have a gray tone that differs only slightly from the aluminum oxide.

Figure 105. Flame-sprayed aluminum oxide coating on steel with Ti02 inclusions, BF. The sample was not mounted before sectioning. Improper sectioning with a high-speed machine has caused the coating to detach from the substrate (as indicated by arrows). The TiOa and the steel substrate have a bright appearance.

Figure 106. Flame-sprayed aluminum oxide coating on steel, with contrast enhanced by Pt/02, BF. The sample was impregnated with epoxy resin before sectioning and then mounted in epoxy resin. The gap at the boundary between the ceramic and the metal (see arrows) is filled with resin, which indicates that this defect was already present before sectioning. The impregnated cavities are dark, the aluminum oxide is gray, and the steel substrate is bright.

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