Plasma sprayed oxides are effective coatings against wear and corrosion. Low particle velocity in the plasma jet causes a limited interlamellar cohesion. HVOF-sprayed ceramic coatings emerged as an improved alternative. In this paper, microstructural characteristics and tribological performances of HVOF sprayed Al2O3, nanostructured Al2O3 and Cr2O3 coatings are compared to reference plasma-sprayed Al2O3 and Cr2O3. The microstructure is analysed by SEM, EDS and XRD. Hardness and fracture toughness are investigated by instrumented indentation and elastic modulus by 3-point bending. Steel wheel and rubber wheel tests have been used to assess dry particle abrasion resistance. Sliding wear resistance is tested by pin-on-disk at room temperature and at 400°C, against SiC and 100Cr6 steel balls. HVOF-sprayed coatings are denser and have better interlamellar cohesion thanks to increased particle velocity. They are harder, tougher, possess a higher elastic modulus and lower porosity. Dry particles abrasion resistance is definitely superior to plasma-sprayed ceramics due to higher toughness; sliding wear resistance is higher, particularly at 400°C.
|Title of host publication||Proceedings of the International Thermal Spray Conference|
|Subtitle of host publication||Thermal Spray 2006|
|Number of pages||6|
|Publication status||Published - 2006|
|MoE publication type||A4 Article in a conference publication|
|Event||International Thermal Spray Conference, ITSC 2006 - Seattle, United States|
Duration: 15 May 2006 → 18 May 2006
|Conference||International Thermal Spray Conference, ITSC 2006|
|Period||15/05/06 → 18/05/06|
Bolelli, G., Cannillo, V., Lusvarghi, L., Turunen, E., Varis, T., Fält, T., & Hannula, S-P. (2006). Wear behaviour of APS and HVOF sprayed ceramic coatings. In Proceedings of the International Thermal Spray Conference: Thermal Spray 2006 ASM International.