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

Rakhadilov, Bauyrzhan; Sulyubayeva, Laila; Maulet, Meruyert; Sagdoldina, Zhuldyz; Buitkenov, Dastan; Issova, Ainur

doi:10.3390/coatings14010011

Cited by 4 publications

(1 citation statement)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Correspondingly, various coating technologies, such as vapor deposition [15], spray coating [16] and plasma electrolytic oxidation [17,18], have been developed to synthesize various coatings (including metallic and ceramic) on metal substrates. Moreover, extensive studies also suggest that the oxidation resistance of coatings can be tailored by controlling their chemical composition [19], microstructure [20] and adhesion strength on a metal matrix (interface) [21,22]. Despite these efforts, the harsh working conditions (high frequency and high-power density) of modern electric industries require a synergetic enhancement of both surface oxidation resistance and electrical conductivity.…”

Section: Introductionmentioning

confidence: 99%

Effect of Copper Surface Roughness on the High-Temperature Structural Stability of Single-Layer-Graphene

Yao,

Zhong,

Guo

et al. 2024

Materials

View full text Add to dashboard Cite

Graphene (Gr) has shown great potential in the field of oxidation protection for metals. However, numerous studies have shown that Gr will suffer structural degradation on metal surface during high-temperature oxidation, which significantly limited the effectiveness of their oxidation protection. Therefore, understanding the degradation mechanism of Gr is of great interest to enhance their structural stability. Here, the effect of copper (Cu) surface roughness on the high-temperature structural stability of single-layer graphene (SLG) was examined using Cu covered with SLG as a model material. SLG/Cu with different roughness values was obtained via high-temperature annealing of the model material. After high-temperature oxidation at 500 °C, Raman spectra analysis showed that the defect density of the oxidized SLG increased from 41% to 81% when the surface roughness varied from 37 nm to 81 nm. Combined with density functional theory calculations, it was found that the lower formation energy of the C-O bond on rough Cu surfaces (0.19 eV) promoted the formation of defects in SLG. This study may provide guidance for improving the effectiveness of SLG for the oxidation protection of metallic materials.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Copper Surface Roughness on the High-Temperature Structural Stability of Single-Layer-Graphene

Yao,

Zhong,

Guo

et al. 2024

Materials

View full text Add to dashboard Cite

show abstract

Development of Method for Applying Multilayer Gradient Thermal Protective Coatings Using Detonation Spraying

Buitkenov,

Nabioldina,

Raisov

2024

Coatings

View full text Add to dashboard Cite

In this work, multilayer gradient coatings obtained by detonation spraying were studied. To obtain a multilayer gradient coating by detonation spraying, two modes with different numbers of shots of NiCrAlY and YSZ were developed. The presented results demonstrate the effectiveness of creating a gradient structure in coatings, ensuring a smooth transition from metal to ceramic materials. Morphological analysis of the coatings confirmed a layered gradient structure, consisting of a lower metallic (NiCrAlY) layer and an upper ceramic (YSZ) layer. The variation in the contents of elements along the thickness of the coatings indicates the formation of a gradient structure. X-ray analysis shows that all peaks in the X-ray diffraction patterns correspond to a single ZrO2 phase, indicating the formation of a non-transformable tetragonal primary (t′) phase characteristic of the thermal protective coatings. This phase is known for its stability and resistance to phase transformation under changing operating temperature conditions. As the thickness of the coatings increased, an improvement in their mechanical characteristics was found, such as a decrease in the coefficient of friction, an increase in hardness, and an increase in surface roughness. These properties make such coatings more resistant to mechanical wear, especially under sliding conditions, which confirms their prospects for use in a variety of engineering applications, including aerospace and power generation.

show abstract

Influence of Spraying Process Parameters on the Characteristics of Steel Coatings Produced by Arc Spraying Method

Rakhadilov,

Magazov,

Kakimzhanov

et al. 2024

Coatings

View full text Add to dashboard Cite

Arc spraying is one of the most effective and cost-efficient thermal spraying technologies for creating high-quality protective coatings. This paper examines the influence of arc spraying process parameters on the properties of steel coatings. The parameters varied in this study included gas pressure, wire feed rate, and the distance from the spray gun to the substrate (standoff distance). Experimental evaluations focused on surface roughness, thickness, porosity, structure, and hardness of the coatings. The techniques used for these evaluations included profilometry for roughness measurement, scanning electron microscopy (SEM) for structural analysis, Vickers hardness testing, and optical microscopy. The results demonstrate a significant influence of arc spraying parameters on the characteristics of the resulting coatings. The analysis revealed that the coatings produced under different modes exhibit a layered structure and vary in thickness. A detailed examination of the coating structure identified defects such as unmelted particles, voids, and delamination in the interface zone. The study of coating thickness and porosity showed that increasing the wire feed rate and decreasing the standoff distance leads to the formation of thicker and denser coatings. Specifically, increasing the wire feed rate from 2 to 12 cm/s resulted in a decrease in porosity from 12.59% to 4.33% and an increase in coating thickness to 699 μm. The surface analysis highlighted the importance of a comprehensive approach to selecting the optimal roughness. While increasing the wire feed rate up to 12 cm/s can increase the Ra roughness parameter, gas pressure also significantly influences this parameter, reducing roughness from Ra = 18.63 μm at 6 MPa to Ra = 15.95 μm at 8 MPa. Additionally, it was found that varying the arc spraying parameters affects the hardness of the coatings, with all modes resulting in hardness values higher than that of the substrate. Therefore, optimizing these parameters enables the achievement of the best combination of mechanical and structural properties in the coatings. These findings can be valuable for further improvement of arc spraying technologies and the expansion of their application across various industries.

show abstract

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

Cited by 4 publications

References 37 publications

Effect of Copper Surface Roughness on the High-Temperature Structural Stability of Single-Layer-Graphene

Effect of Copper Surface Roughness on the High-Temperature Structural Stability of Single-Layer-Graphene

Development of Method for Applying Multilayer Gradient Thermal Protective Coatings Using Detonation Spraying

Influence of Spraying Process Parameters on the Characteristics of Steel Coatings Produced by Arc Spraying Method

Contact Info

Product

Resources

About