Preparation of composite powder based on nano-TiO2 and Cr2O3 using a spray dryer, for atmospheric plasma spraying, designed for HPAL systems
Rakhadilov B. Turar Z. Kakimzhanov D. Kengesbekov A.
May & June 2025OICC Press
Journal of Theoretical and Applied Physics
2025#19Issue 3
In this study, composite coatings based on TiO2 and TiO2-Cr2O3 nanopowders were fabricated by air plasma spraying for High-Pressure Acid Leaching (HPAL) systems. Nanopowders were agglomerated in aqueous medium using polyvinyl alcohol and spray-dried into spherical granules. Coatings were deposited onto 12Kh18N10T stainless steel substrates. X-ray diffraction (XRD) analysis revealed rutile TiO2 and Cr2O3 as the main crystalline phases, with minor Ti2O3. For TiO2-only coatings, the XRD pattern showed predominantly rutile (R-TiO2) and a small amount of anatase (A-TiO2); brookite was absent. Rutile formation is attributed to high plasma spraying temperatures that promote anatase-to-rutile transformation. The coatings had dense microstructures with low porosity due to optimized powder preparation and spraying. Microhardness of TiO2-Cr2O3 coatings reached 1015 HV, 40% higher than pure TiO2 (723 HV). Tribological tests under a 3 N load and 500 m sliding distance showed a reduced friction coefficient from 0.98 to 0.65. The wear rate of TiO2-Cr2O3 coatings was 4.2 × 10−5 mm3/N.m, indicating enhanced wear resistance. These findings demonstrate that Cr2O3 addition and optimized powder processing yield harder, denser, and more durable coatings, suitable for harsh service conditions.
Agglomeration , Coatings , Microhardness , Plasma spraying , Structure , Wear resistance
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Plasma Science LLP, Ust-Kamenogorsk, 070000, Kazakhstan
Sakarya University, Thermal Spray Research and Application Laboratory, Sakarya, 54050, Turkey
Plasma Science LLP
Sakarya University
10 лет помогаем публиковать статьи Международный издатель
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