SURFACE & COATINGS TECHNOLOGY
·
2021
·
IF 4.158
Ying Wang,Yanhong Liu,Guangbin Li,Mingmin Zheng,Yusha Li,Anlei Zhang,Yingchun Zhang
In this study, Cr coatings were electrodeposited on carbon steel substrates by a trivalent Cr salt. The microstructure of the Cr coatings and their flow accelerated corrosion (FAC) resistance in simulated secondary circuit environments (10 MPa and 150 °C) of nuclear power plants were investigated. The results showed that the as-deposited coating was amorphous and crack-free. Annealing at 200 °C resulted in the decrease of Cr (OH) 3 and the increase of Cr and Cr 2 O 3 on the coating surface , which improved the corrosion resistance of the coating. The subsequent FAC test showed that the Cr coatings significantly improved the FAC resistance of the carbon steel substrate. The coating annealed at 200 °C exhibited better FAC resistance. The Cr-rich oxide film formed on the coatings was mainly Cr 2 O 3 , with a small amount of Cr and CrO 2 . Due to the galvanic effects caused by pinhole defects, abnormally grown annular deposits formed on the coating surface.
研究领域:
材料科学
·
腐蚀与防护
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 29
·期 5
·4179-4189
·
IF 2.019
Han Xiaopeng,Huang Ying,Zhou Suhua,Sun Xu,Peng Xuanyi,Chen Xuefang
Due to the high agglomerate propensity of Si particles, making aluminum composites with a dispersion of the reinforcement using traditional way is still a challenge. In this study, an innovative approach was utilized to prevent the agglomeration of particles using encapsulating graphene sheets by grinding. Afterwards, the milled mixtures were incorporated with Cr-coated graphite flakes, urea and starch via mechanical mixing. After being mechanically mixed and sintered at 330 °C, the porous preform was fabricated by vacuum gas pressure infiltration. Effects of graphene content (0.5, 1, 3, 5 wt%) on the microstructures and properties of thermal and mechanical were investigated. Thermal conductivity and bending strength of the graphite flakes (G f )/Si/Al composites increased by 41.4 and 300%, respectively compared to the specimens without graphene. G f /Si/Al composites with graphene mass fraction of 5% had excellent in-plane thermal conductivity of 346 W/mK and bending strength of 84 Mpa, suggesting the composites can be applied as promising thermal management materials.
研究领域:
材料科学
·
工程学
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2025
·Vol. 172
·期 9
·092505
·
IF 3.3
Chuntao Ge,Qian Kou,Rong Li,Wenjuan Qi,Junjie Xu,Jun Zhang,Saijun Xiao
The NaCl-CaCl2 molten salt system presents a cost-effective and stable medium for the electrodeposition of metallic chromium. However, the electrochemical behavior of Cr2+ and the deposition process for dense chromium coatings within this system remain unexplored. Using CrCl2 as a precursor, this study investigated the electrochemical behavior of Cr2+ in NaCl-CaCl2 molten salt at 620 °C through cyclic voltammetry and square wave voltammetry. The results revealed that the reduction of Cr2+ involved a one-step, two-electron exchanged reaction (Cr2++ 2e−→Cr), exhibiting quasi-reversible behavior controlled by diffusion, with a diffusion coefficient of 0.5 × 10–5 cm2s−1. Electrodeposition on a molybdenum substrate demonstrated that current density significantly influenced coating morphology. An optimal condition of 30 mA cm−2 yielded a dense and uniform chromium coating, whereas current densities of 50–70 mA cm−2 resulted in significant degradation in coating planarity due to concentration polarization. Deposition time exhibited a linear positive correlation with coating thickness. Extending deposition time eliminated initial island growth and enhanced coating continuity. X-ray diffraction confirmed the coating consisted of pure chromium phase with a strong (200) preferred orientation. This research provided a theoretical and experimental foundation for electrodepositing chromium metal coatings in the NaCl-CaCl2 molten salt system.
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DOI
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
·
2022
·
IF 4.514
Jianqiao Yang,Jiyuan Sun,Shuyuan Bai,Hao Wu,Shuzhong Wang,Yanhui Li,Wenhao Ma,Donghai Xu
To improve the corrosion resistance of component materials in supercritical water oxidation (SCWO) environment, a 15 µm Cr coating was prepared on Alloy 625 by magnetron sputtering, and the effect of oxygen concentration (0 M, 0.16 M, and 0.94 M) on the stability of the Cr coating in an SCW environment was investigated. Results show that the stability of the Cr 2 O 3 layer strongly depends on the oxygen concentration in the exposure environment. The protective Cr 2 O 3 layer was transformed to soluble Cr(VI) species and dissolved in SCW containing 0.94 M oxygen. Except for Cr 2 O 3 , some Fe/Ni containing oxides were also detected. The stability of the Cr coating in SCW with different concentrations of oxygen is discussed.
研究领域:
材料科学
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腐蚀与防护
·
表面工程
·
能源环境工程
·
高温化学
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DOI
高影响因子
JOURNAL OF SUPERCRITICAL FLUIDS
·
2024
·
IF 3.4
Jianqiao Yang,Yining Ding,Fen Zhao,Shuzhong Wang,Yanhui Li,Donghai Xu
In this study, a Cr coating was fabricated on Ni-based alloys to prevent under-deposit corrosion. The effect of salt deposition on the structural integrity of the Cr coating in SCW environment with/without oxygen was investigated. Results show that the Cr coating kept its integrity after exposure in SCW environment, successfully avoided the metallic ions leaching from Ni-based alloys. The structure of the oxide layer after exposure is a thin Fe 2 O 3 or FeCr 2 O 4 layer and a Cr 2 O 3 layer. The oxidation rate of the Cr coating decreased to one third of the sample after exposure in the same environment without salt deposit layer, indicating that the inward mass-transfer of oxygen to the alloy surface was inhibited by the salt deposit layer. The volume expansion of the sample due to the growth of Cr oxide layer was restrained by the salt deposit layer, forming a growth stress in the coating.
研究领域:
材料科学
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腐蚀科学
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高温材料学
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表面工程
·
能源材料
·
化学工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·Vol. 51
·期 14
·19058-19070
·
IF 5.6
Ming-Xi Li,Wei Wei,Yibo Zhao,Ming Li,Haibo Huang,Zhe Chen,Xiao-Ming Xie,Xiu-Bo Liu
Improving the fracture toughness of agricultural soil-engaging components can mitigate the detrimental effects of hard particles in the soil while maintaining the wear resistance of the components, thereby improving the service performance. The wear resistance of the parts can be improved by surface treatment, but the surface toughness after treatment still needs to be further improved. In this study, WC10Co4Cr@YSZ (Yttria Stabilized Zirconia) core-shell structured composite powder was synthesized by modifying commercial WC10Co4Cr powder using the sol-gel method, and WC10Co4Cr coatings were prepared using the powders before and after modification. The microstructure of the powder and coatings were characterized. The mechanical properties and wear resistance of the coatings were evaluated through microhardness , nanoindentation , and friction testing. The hardness of the YSZ-modified composite coating was comparable to that of the unmodified coating, yet it exhibited lower porosity and twice the fracture toughness. Wear test results indicated that the coating's wear loss was greatly reduced compared with the substrate. In addition, the wear rate of the YSZ-modified coating was 71.11 % lower than the unmodified coating, demonstrating its exceptional wear resistance. The findings show that incorporation of YSZ into the coating system further enhanced wear resistance. The strengthening mechanisms resulting from the YSZ inclusion include the pinning effect, which controls the size and distribution of the WC grains, the shell structure that prevents overheating, and the improved fracture toughness of the coating. This work provides a new way to extend the service time of agricultural soil-engaging components.
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DOI
高影响因子
危险品化学品经营许可证（带存储）