Changes in the structure and properties of ZrO2 detonation coatings during annealing

Abstract

The article studied the effect of annealing on the structure and properties of zirconium dioxide coatings obtained by detonation spraying. Detonation spraying was realized on a computerized detonation spraying complex of the new generation CCDS2000. Determined that coatings made of zirconium dioxide are characterized by high adhesive strength of adherence to the substrate. Thermal annealing of coated samples was performed at temperatures of 900-1200◦ C. It was determined that the microhardness of zirconium dioxide coatings increases by 10-25% depending on the annealing temperature after annealing. The results of nanoindentation showed that the nanohardness of the coatings after annealing at 1000◦ C increases by 50%. It was determined that after annealing at 1000◦ C, the elastic modulus of the coatings increases, which indicates a decrease in plasticity and an increase in the strength of the coatings. X-ray diffraction analysis showed that the phase composition of coatings before and after annealing consists of t-ZrO2. After annealing occurs there is an increase in the degree of t-ZrO2 tetragonality. Electron microscopic analysis showed that an increase in the number and size of micro-continuity in the form of thin layers after annealing. Determined that increase the hardness of zirconium dioxide after annealing at 900-1200◦ C is associated with a higher degree of tetragonality t-ZrO2 phase.

Investigation of High-Temperature Oxidation of Homogeneous and Gradient Ni-Cr-Al Coatings Obtained by Detonation Spraying

“…SEM images of cross sections of homogeneous and gradient Ni-Cr-Al coatings after testing are shown in Figure 6. As can be seen in the image, the average thickness of the coating after the tests is 140-160 µm while, before the tests, it was 90-110 µm [27]. After the high-temperature cyclic oxidation test, the Ni-Cr-Al coatings did not show cracks and delamination.…”

“…Coatings 2024, 14, x FOR PEER REVIEW 8 of 11 µm [27]. After the high-temperature cyclic oxidation test, the Ni-Cr-Al coatings did not show cracks and delamination.…”

“…Homogeneous and gradient Ni-Cr-Al coatings were applied to all six sides of the substrates. Table 2 shows the modes of obtaining homogeneous and gradient coatings based on Ni-Cr-Al [27]. The investigation focused on studying the cyclic oxidation characteristics of both uniform and graded coatings based on Ni-Cr-Al.…”

“…This intentional design facilitates the formation of a sufficient amount of Al 2 O 3 on the coating surface. In our subsequent work [27], we compared the structure and properties of homogeneous and gradient coatings based on Ni-Cr-Al obtained through detonation spraying. The primary objective of this research is to explore the high-temperature oxidation of homogeneous and gradient coatings based on Ni-Cr-Al, obtained by detonation spraying.…”

Study of the Structural-Phase State of Hydroxyapatite Coatings Obtained by Detonation Spraying at Different O2/C2H2 Ratios

“…The titanium substrates were sandblasted before coating. A computer-controlled CCDS2000 (LIH SB RAS, Novosibirsk, Russia) detonation spraying unit was used for coating [23]. The detonation gun barrel had a length of 450 mm and a diameter of 26 mm.…”