Abstract: |
Thermally sprayed ceramic coatings are used in environments requiring good wear- and corrosion resistance among others. However, a typical issue with ceramic coatings is their low impact resistance and tendency to fail catastrophically by cracking. In bulk ceramics, the Al2O3-ZrO2composition has been of interest for long since already small additions of ZrO2 to Al2O3 have shown improvements in fracture toughness compared to pure Al2O3. Efforts are being made to induce this increase resistance to fracturing in thermally sprayed coatings as well, resulting in higher wear resistance due to a more predictable behavior and damage-tolerance. In this work, Al2O3-ZrO2-coatings have been deposited by atmospheric plasma spray (APS) and high-velocity oxy-fuel spray (HVOF). The wear characteristics of the coatings were evaluated with rubber-wheel abrasion, solid particle- and cavitation erosion tests. Differences in the results were interpreted based on coating structure as analyzed by electron microscopy and x-ray diffraction. The HVOF-sprayed coatings showed vast improvements in the tests.
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