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15 November 2025, Volume 58 Issue 11
  
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  • LIU Jie, LIU Yan, YANG Bing
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    High-entropy alloys (HEAs) coatings have emerged as potential candidate materials for protective coatings due to their excellent mechanical properties, wear resistance, corrosion resistance, and high-temperature oxidation resistance.However, the interactions and synergistic mechanisms among the different elements in HEAs coatings remain unclear.To investigate the interactions and synergistic mechanisms among the different elements in high-entropy alloys coatings, four AlCrNbSiTi HEAs coatings with different compositional ratios were fabricated via magnetron sputtering using targets of varying composition.In addition, the coatings were thoroughly characterized by SEM, AFM, EDS,XRD, ball-on-disc tribometer and electrochemical workstation to investigate their morphology, chemical composition, structure, mechanical properties and electrochemical corrosion behavior.Results showed that the increase in Cr content resulted in a greater atomic size difference within the coating, thereby reducing the degree of ordered arrangement in its internal structure.The increase in Cr and Nb contents contributed to enhancing the scratch toughness of the coating and significantly reducing its wear rate.Furthermore, Ti atoms within the coating were found to provide a dual-layer protection effect on both the passive film/solution interface and the coating/passive film interface, which enhanced the stability of the passive film and consequently improved the corrosion resistance of the coating.
  • YOU Shilong, GUAN Mengxue, FAN Qixiang, CAO Fengting, LIU Yanmei, WANG Tiegang
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    To investigate the effect of modulation period on the properties of AlCrSiN/AlTiN nanomultilayer coatings, AlTiN and AlCrSiN monolayer coatings, along with two types of AlCrSiN/AlTiN nanomultilayer coatings with different modulation periods, were fabricated using arc ion plating, direct current magnetron sputtering, and a hybrid deposition technique combining both methods.Subsequently, the phase structure,microstructure, mechanical characteristics and tribological performance of the coatings were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindenter and other complementary techniques.Results revealed that in contrast to AlTiN and AlCrSiN monolayer coatings exhibiting a (111) preferred orientation, the AlCrSiN/AlTiN nanomultilayer coatings developed a face-centered cubic(fcc)-(Al,Cr,Ti)N solid solution with a (200) preferred orientation.The surface roughness of the two multilayer coatings was lower compared to the monolayer coatings, and with an increase in the modulation period, the surface quality of the coatings exhibited a gradual improvement,accompanied by a smoother and more distinct interlayer interface.Mechanical property assessments indicated that the AlCrSiN coating fabricated via magnetron sputtering exhibited the lowest hardness,which measured 16.57 GPa,whereas the multilayer coating with Λ=106 nm demonstrated the highest hardness, which reached 36.63 GPa, suggesting that the multilayer architecture can enhance the hardness of the coating.Despite possessing fewer interfaces compared to the coating with Λ=91 nm, the coating with Λ =106 nm exhibited a higher hardness, which might be attributed to its smoother interface morphology and lower surface roughness.Furthermore, the multilayer coating with Λ =106 nm exhibited the highest resistance to plastic deformation (H3/E*2 value,0.147 GPa), the greatest adhesion strength (58.29 N), and the lowest wear rate [5.3×10-6 mm3/(N·m)], suggesting its superior mechanical properties of a multilayer architecture.This study revealed that adopting a multilayer structure design and appropriately adjusting the modulation period could significantly enhance the mechanical properties and anti-friction-wear performance of coatings.The findings of this research offer valuable guidance for the performance enhancement and engineering application of AlCrSiN/AlTiN multilayer coatings.
  • FAN Mingzhen, LUO Chaoyong, WANG Hui, GU Baojun, DONG Xue, ZHANG Yan, DU Pengcheng
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    To investigate the influence of coating fracture toughness on tribological properties, Cr3C2-NiCr and WC-17Co coatings were deposited on 30CrMnSiA alloy steel substrates using the high-velocity oxygen-fuel (HVOF) spraying method.The microstructure and mechanical properties of the coatings were characterized by scanning electron microscopy (SEM) and Vickers hardness tester.The tribological properties of two types of coatings (Cr3C2-NiCr and WC-17Co) against a 30CrMnSiA friction pair under dry sliding conditions were evaluated by multifunctional tribometer.Results showed that the microhardness of Cr3C2-NiCr and WC-17Co coatings was close, being 1 068 HV0.3 and 1 126 HV0.3,respectively.However, the fracture toughness of the Cr3C2-NiCr coating was measured as 2.45 MPa·m1/2, significantly lower than that of the WC-17Co coating (4.66 MPa·m1/2).Under dry friction conditions, the Cr3 C2-NiCr coating was more prone to fatigue cracking than the WC-17Co coating, resulting in particle detachment and the formation of abrasive particles, which further caused severe abrasive wear to the coating and the friction pair.The wear rate of Cr3C2-NiCr was 1.23×10-7 mm3/(N·m), higher than that of WC-17Co coating [0.93×10-7 mm3/(N·m)].Additionally, the wear weight loss of the 30CrMnSiA friction pair sliding against the Cr3C2-NiCr coating was 9.82 mg, which was higher than that of the 30CrMnSiA friction pair sliding against the WC-17Co coating (8.43 mg).
  • ZHAO Xinjie, HE Lei, XU Yi, XIA Yuan, LI Guodong
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    To enhance the mechanical properties and corrosion resistance of AlTiSiN nanocomposite coatings, AlTiSiN coatings were deposited on titanium substrates using high-power impulse magnetron sputtering (HiPIMS), and the effects of different bias voltages on the microstructure, mechanical properties, and corrosion resistance of the coatings were systematically investigated via X-ray diffraction (XRD), scanning electron microscopy (SEM), nanoindentation tester, and electrochemical workstation.Results showed that with increasing bias voltage, the thickness of the AlTiSiN coatings gradually decreased, and the deposition rate dropped from 18.33 nm/min to 13.70 nm/min.The substrate phase (α-Ti) exhibited distinct diffraction peak intensities, while the diffraction peak observed at 2θ ≈27° was attributed to the (200)crystal plane of β-Si3N4, showing significant broadening.The nanohardness and Young’s modulus of the coatings initially increased and then decreased with increasing bias voltage, reaching their maximum values of 16.59 GPa and 233.33 GPa at a bias voltage of 160 V.Moreover,when the bias voltage was set at 160 V, the AlTiSiN coating exhibited the lowest corrosion current density (1.04 × 10-4 mA/cm2), the highest polarization resistance (2.77 × 105 Ω·cm2) and the maximum inhibition efficiency (98.74%),demonstrating its optimal corrosion resistance.Therefore, the applied bias voltage significantly influenced the microstructure, mechanical properties, and corrosion resistance of the coatings.The AlTiSiN coating prepared by HiPIMS at a bias voltage of 160 V effectively enhanced the surface quality and mechanical properties.The coating exhibited lower corrosion current density, higher polarization resistance, and improved inhibition efficiency, resulting in enhanced corrosion resistance.
  • XU Mengjiao, LIU Yanmei, YIN Zhaoxing, SHI Zhuang, ZHUANG Siming, WANG Peng, WANG Tiegang
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    To enhance the toughness of ZrB2 coatings, the composite technology of high-power pulsed magnetron sputtering and pulsed direct current magnetron sputtering was utilized to incorporate C elements into ZrB2 coatings and further prepare Zr-B-C coatings with different carbon contents by adjusting the acetylene flow rate.The phase composition and microstructure of the coatings were characterized by X-ray diffraction(XRD) and scanning electron microscopy (SEM), and the mechanical properties of the coatings were systematically analyzed using a nanoindentation tester and a scratch tester.Meanwhile, the friction and wear performance and surface wear mechanism of the coatings were investigated by a friction and wear tester and a super-depth-of-field microscope.Results showed that as the acetylene flow rate increased, the carbon content within the Zr-B-C coatings rose, leading to a structural transformation from a porous columnar crystal structure to a dense nanocomposite structure.The hardness, wear rate, critical load, and residual stress of the coatings initially decreased, then increased, and finally decreased again.In addition,the friction coefficient,H/E ratio and H3/E*2 ratio first rose and then declined,while the elastic modulus exhibited a consistent downward trend.When the acetylene flow rate was 10 mL/min, the Zr-B-C coating demonstrated excellent tribological performance, with a hardness of 23 GPa, a friction coefficient of 0.909, and a wear rate of 2.3 × 10-7 mm3/(mm·N).
  • MA Sanbao, JIA Dan, HUANG Ruihua, XU Zhengtian, SHI Zhijun, XING Xiaolei, YANG Qingxiang, ZHOU Yefei
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    In order to investigate the microstructure and properties of Ti3 AlN coatings under different bias voltages and nitrogen flow rates,Ti3AlN coatings were prepared using vacuum cathode deposition technology under varying bias voltages and nitrogen flow rates, and their deposition rate, surface roughness, hardness, adhesion strength and friction coefficient were systematically characterized.Results showed that with the increase of nitrogen flow rate, the coating deposition rate increased, the surface roughness decreased, the hardness and adhesion rose,and the friction coefficient exhibited a slight reduction.With increasing bias voltage,the coating deposition rate initially rose and then declined,the surface roughness first increased and then decreased, while both hardness and adhesion strength improved; additionally, the friction coefficient reached a higher value at a bias voltage of 200 V.When the bias voltage was 100 V and the nitrogen flow rate was 60 mL/min, the adhesion strength of the Ti3AlN coating reached the optimal level of 72.3 N,meanwhile the friction coefficient reached the lowest value.The findings of this study provide a theoretical basis for optimizing the preparation process of Ti3AlN coatings.
  • WU Meiling, FENG Yi, JIANG Qili, CHE Zhiqiang, DU Yukang, YANG Longgang, LANG Xiaoyue, WANG Kesheng, OU Yixiang
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    In order to systematically explore the regulation law of substrate bias on the structure and performance of Cr/CrN/WC composite coatings prepared by high-power pulsed magnetron sputtering (HiPIMS),Cr/CrN/WC composite coatings were deposited on AISI 304 stainless steel substrates by high-power pulsed magnetron sputtering, and the influence of substrate bias voltage (0 to -300 V) on the structure, mechanical and tribological properties of coatings was investigated systematically.X-ray diffraction (XRD) and scanning electron microscopy(SEM) characterization revealed that as the bias voltage increased to -200 V, the β-WC1-x(200) crystal plane exhibited enhanced preferred orientation, along with refined grains, weakened columnar structure, and significantly improved density.However, at the bias voltage increased to -300 V,excessive ion bombardment induced lattice defects,causing a decrease in density.Mechanical property tests indicated that the coating deposited at -200 V achieved a synergistic enhancement of strength and toughness, exhibiting peak nanohardness (43.25 GPa) and effective Young’s modulus (474.77 GPa).The hardness/modulus ratio (H/E*=0.091) and plastic deformation resistance parameter (H3/E*2 =0.359 GPa) increased by 19.7%and 91.0%, respectively, compared to the 0 V sample.In addition, Rockwell C indentation tests further confirmed that the coating's adhesion strength achieved grade HF1 (optimum), with no crack formation or delamination observed around the indent, which was attributed to the high elastic strain coordination of the high H/E* ratio and the high interfacial stress suppression of the high H3/E*2 value.Tribological test results demonstrated that the coating deposited at the bias voltage of -200 V exhibited the lowest coefficient of friction (0.42) and the minimum wear rate [1.39 × 10-7 mm3/(N·m)],owing to the high hardness and low surface roughness,and the wear mechanism was mild oxidative-adhesive wear.In contrast, the coatings deposited at 0 V and -300 V showed higher wear rates [2.78 × 10-7 mm3/(N·m) and 1.85×10-7 mm3/(N·m)], and their wear mechanisms were abrasive-oxidative composite wear and soft phase-induced abrasive wear, respectively.In summary, the -200 V bias voltage achieved quaternary synergistic optimization of hardness, toughness, adhesion strength and wear resistance through the grain refinement and structural densification, while the excessive bias voltage (-300 V) led to coating performance degradation due to lattice damage and interfacial weakening.
  • CHEN Zhinan, JIANG Zelin, LI Ruifeng, CHEN Yongxiong
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    As additive manufacturing (AM) continues to evolve towards system integration and intelligent control, issues such as cross-stage information discontinuity, fragmented control mechanisms, and unpredictable performance responses have become increasingly prominent.Endto-end additive manufacturing, centered on the interconnection of structure, process, and performance, leverages digital technologies to bridge traditionally isolated stages.This integration enables multi-stage coordination and closed-loop process control,thereby providing critical support for the fabrication of high-performance, high-consistency complex components.This system featured strong multiphysics coupling, high-dimensional parameter spaces, multi-objective constraints, and dynamic state evolution, and put forward higher requirements for information perception, modeling optimization, and control feedback throughout the entire process.Focusing on the systematic workflow from design to manufacturing in additive manufacturing,this article reviewed research advances in simulation-driven structural design,process modeling and manufacturing optimization, in-process monitoring and feedback control,as well as system integration and data collaboration.Specifically,the application practices of mainstream modeling strategies, perception and control methods, and integrated frameworks in enhancing manufacturing process stability and consistency were summarized.Furthermore, combining complex service requirements such as material protection, the study analyzed key challenges in system integration capability, state recognition accuracy, and performance-oriented control mechanisms, and prospected the development trends for constructing additive manufacturing systems with real-time sensing, intelligent response, and closed-loop control capabilities.
  • ZHOU Yuhao, CAI Xinrui, WANG Yanhui, SUN Jinfeng
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    TiO2 has wide applications in photocatalysis and electrochemical energy storage,but it also faces certain limitations.The high recombination rate of TiO2 photogenerated charge carriers and low light absorption efficiency restrict its photocatalytic efficiency in the field of photocatalysis.In electrochemical energy storage, as an anode material for lithium-ion batteries, TiO2 suffers from poor electrical conductivity and low ionic mobility, and its practical specific capacity remains to be improved.By controlling the electrical parameters and electrolyte composition in the micro-arc oxidation (MAO) process, it is possible to effectively regulate the composition, phase composition and surface morphology of the oxide film, simplifying the modification process.Applying high voltage to titanium or titanium alloys in the electrolyte allows for the in-situ formation of self-supporting porous TiO2 oxide films on the surface.TiO2 films prepared via MAO exhibit a large specific surface area,which can load more active substances, enhancing electrical conductivity and ionic mobility, thereby improving both their catalytic activity and electrochemical energy storage performance.This opens new pathways for the application of TiO2 in the fields of photocatalysis and electrochemical energy storage.This paper reviewed the applications and research progress of TiO2 prepared by MAO in recent years in the fields of photocatalysis and electrochemical energy storage.The basic principles of MAO were introduced,and the effects of electrolyte composition,electrical parameters and oxidation time on the morphology, phase composition, optical properties and electrochemical performance of TiO2 were elaborated.Finally, the potential and challenges of MAO technology in photocatalysis and electrochemical energy storage applications were explored.
  • ZHANG Junwei, DAI Jingjie, WANG Amin, HU Ming
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    Magnesium and its alloys have attracted significant attention owing to their unique microstructure, mechanical properties, degradation performance and biocompatibility, but their excessively rapid degradation rate limits their practical applications.Because of its excellent biocompatibility, hydroxyapatite (Hydroxyapatite, HA) can enhance the biocompatibility and corrosion resistance of magnesium and its alloys when preparing Mg-based HA biomaterials, and exhibits effective degradation rate modulation capability.Firstly, the preparation methods of Mg-based HA biomaterials were introduced in detail in this work.Subsequently, the effects of different alloying elements, metal oxides and organic compounds on the properties of these Mg-based HA biomaterials were thoroughly discussed.Moreover, the mechanical properties, electrochemical corrosion behavior, in vitro degradation performance, biocompatibility and bioactivity of Mg-based HA biomaterials were systematically reviewed.Finally, the main challenges currently faced by Mg-based HA biomaterials were summarized, and future development trends were outlined.
  • YUE Yingchao, LYU Wangyan, WANG Zhong’ao, NIE Ming, LIANG Yongchun, WANG Linli, ZHANG Hao, DONG Chaofang, XIAO Kui
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    To evaluate the corrosion behavior and mechanisms of T2 copper in a subtropical hot-humid coastal atmospheric environment,and to provide data support for the durability design and material selection of electrical power facilities, this study focused on the T2 copper material commonly used in power grid systems.By analyzing the meteorological environment and pollutant ion data of coastal cities in a subtropical humid atmosphere, a corrosion prediction model was established using the weight loss method.The corrosion morphology of the samples was observed by scanning electron microscopy (SEM), and the composition of corrosion products was analyzed using X-ray diffraction (XRD).Combined with electrochemical analysis, the electrochemical behavior of T2 copper in the simulated subtropical hot-humid atmospheric environment was investigated.Results showed that the primary form of corrosion for T2 copper in the simulated subtropical hot-humid atmospheric environment was uniform corrosion, and the corrosion prediction model followed a power function model.The corrosion products were mainly composed of CuO and Cu2O, with the proportion of Cu2O gradually increasing with the extension of the test period.The semiconductor properties of Cu2O helped to suppress the diffusion of the corrosive medium,thus providing protection for the substrate.This study provided reference data for the material selection and corrosion prevention design of electrical power facilities operating in simulated subtropical hot-humid atmospheric environment.
  • WANG Jie, ZHANG Wulin, FAN Xiaoqiang, CHENG Yu, YUAN Yongjie, JIA Dan
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    In order to systematically investigate the influence of resin flowability on the key performance characteristics of rail grinding stones(GS) and the surface quality of rails post-grinding, three groups of GS materials were prepared using resins with low (Pr-S), medium(Pr-M), and high (Pr-L) flowability.The compressive strength, grinding mass, grinding ratio and wear morphology of the three groups were analyzed.The surface quality and oxidation behavior of the ground rails were characterized, and the correlation between their formation and resin flowability was discussed.Results showed that the GS with medium flowability (Pr-M) exhibited optimal overall performance: the highest compressive strength (154.3 MPa), the highest grinding ratio (16.0), the lowest surface roughness (6.5 μm) and the minimal white layer thickness (17 μm), with a uniform wear mechanism.Excessively low resin flowability (Pr-S) led to abrasive detachment (strong self-sharpening), with a maximum grinding mass of 1.0 g but a low grinding ratio.This caused higher grinding temperatures, resulting in severe oxidation of the rail surface, with an 88.2%increase in white layer thickness compared to that of the GS with medium flowability (Pr-M).Pr-L led to binder loss and macroscopic fracture of the grinding stones, reducing both grinding capability and wear resistance.Resin flowability is a critical factor determining both grinding stone performance and rail surface quality.Medium-flowability resins should be prioritized in GS development,supplemented with compatible pore-forming technologies to further enhance their grinding capability, thereby improving overall grinding efficiency, rail surface quality and operational safety.
  • SONG Yinggang, LUO Xuekun, WANG Xin, FENG Yefei, TIAN Gaofeng
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    In order to improve the high-temperature performance of turbine discs, an ultrasonic shot peening test was conducted on FGH99 alloy for turbine discs.The microstructure and fatigue properties of FGH99 alloy after ultrasonic shot peening treatment were analyzed experimentally using scanning electron microscopy (SEM),microhardness testing, residual stress measurements and fatigue testing.Results showed that as the amplitude of ultrasonic shot peening increased, the surface roughness of FGH99 alloy gradually increased.The Sku value of the crater root fillet gradually approached 3.Ultrasonic shot peening introduced a strengthening layer on the surface of FGH99 alloy, with a maximum depth of 290 μm, primarily composed of dislocations and twins.The hardness of the surface layer increased by 21.7%compared to the substrate.The maximum residual stress reached -1 150 MPa.The fatigue limit of FGH99 alloy increased from 700 MPa in the grinding state to 765 MPa.Furthermore, fatigue cracks originated from the subsurface of the specimen, indicating that the fatigue life depended on material defects rather than surface morphology.
  • ZHANG Jintao, JIANG Ding, WU Hao, ZHANG Jianyuan, REN Lu, SUO Xinkun
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    In this study, AlFeCrNiCu high-entropy alloy (HEA) coatings were prepared using laser cladding, and the effects of laser power(2 400, 3 000,3 600 W) and scanning speed (0.15,0.25,0.35 m/s) on the microstructure and wear resistance of the coatings were investigated.The phase composition, microstructure, microhardness and wear resistance of the HEA coatings were analyzed using X-ray diffraction(XRD), scanning electron microscopy (SEM), a Vickers microhardness tester, and a high-frequency reciprocating wear testing machine, respectively.Results showed that the dilution rate decreased with increasing scanning speed.As laser power increased, the dilution rate increased, and the number of cracks and other defects decreased.The dilution rate reached its minimum value (40.62%) when the scanning speed was 0.35 m/s and the laser power was 2 400 W.The phase structure of the AlFeCrNiCu HEA coatings consisted of FCC and BCC phases, with the BCC phase being dominant.The coatings consisted mainly of columnar crystals,and an increase in scanning speed led to grain refinement.The average microhardness decreased from (593.70±14.27) HV0.2 to (553.6±11.43) HV0.2 as the laser power increased from 2 400 W to 3 600 W when the scanning speed was 0.15 m/s.However, the microhardness of the coatings increased with increasing scanning speed,indication an improvement in the wear resistance of the coatings.When the scanning speeds were 0.15 m/s and 0.25 m/s, the wear rate of the coatings decreased with increasing scanning speed, indicating an improvement in the wear resistance of the coatings.The main wear mechanism of the coatings was three-body wear.
  • WANG Fengtao, ZHAO Kangwei, YANG Jianjun, FAN Ming, LUO Deng, CHEN Qian, GUO Hongyan, FAN Caihe, LIU Danyang, LIU Ximao, XIONG Xiangjiang, LI Fangfang, WANG Jiwen
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    In order to evaluate the effects of different stabilizing agents and improve the corrosion resistance of Q420qNH steel under actual service conditions,and provide guidance for the practical application of weathering steel.Based on previous work,two groups of stabilizing agents with superior performance were selected [Group C: 0.5%FeSO4, 0.5%NiSO4, 0.6%CuSO4, 0.5%Na3PO4, 0.5%Fe3O4, 0.1%Ce2(SO4)3, by mass fraction, the same below; Group F: 0.5%FeSO4, 0.5%NiSO4, 0.6%CuSO4, 0.5%NaMoO4, 0.5%Fe3O4, 0.1%Ce2(SO4)3].The Q420qNH weathering steel test specimens were subjected to an 8-cycle stabilization treatment in the laboratory,followed by a 3-month industrial atmosphere exposure test.The corrosion resistance of the rust layers on specimens with and without stabilization treatment,as well as those treated with different stabilizing agents, was comparatively investigated using corrosion kinetics, X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical analysis.Results showed that under industrial atmosphere exposure, the stabilized specimens exhibited a higher initial corrosion rate,which decreased in later stages.The formed rust layer displayed fewer defects such as cracks and pores,along with improved compactness.The rust layers of both untreated and treated specimens were primarily composed of α-FeOOH, γ-FeOOH, β-FeOOH and Fe3O4/γ-Fe2O3 phases.After stabilization treatment, the content of α-FeOOH increased, with the highest content (53%) observed in Group C.Among all specimens, those treated with Group C stabilizing agent exhibited the densest rust layer, the highest self-corrosion potential, and the strongest corrosion resistance, followed by Group F, while the bare steel performed the worst.The stabilizing agents shortened the stabilization period of the rust layer.Group C stabilizing agent demonstrated the best effect on promoting the formation of a stable rust layer.
  • JIANG Songtao, LI Yeqing, YU Songbai, WANG Yunyao
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    Superhydrophobic thermal insulation coatings can significantly reduce energy consumption and effectively protect substrates from contamination and damage caused by oil, mold, and other pollutants.However, traditional superhydrophobic thermal insulation coatings are limited in their application across multiple fields due to defects such as poor mechanical properties, complex processing, and high thermal conductivity.To address this, a novel composite aerogel with an HNTs/SiO2 ball-stick network structure was prepared using the sol-gel method, with tetraethyl orthosilicate (TEOS) as the silicon source and halloysite nanotubes (HNTs) as the reinforcing phase, followed by CO2 supercritical drying.After grinding the composite material to a specific fineness, it was uniformly mixed with an aqueous polyurethane dispersion and a low-surface-energy substance, 1H,1H,2H,2H-perfluorodecyltriethoxysilane.This mixture was sprayed onto the substrate surface, and after curing, a wear-resistant superhydrophobic thermal insulation coating was formed.The structure was characterized by Fourier-transform infrared spectroscopy (FT-IR), the microstructure and wettability of the coating were analyzed using scanning electron microscopy (SEM) and contact angle analyzer (DCA), and the coating's wear resistance and thermal insulation properties were tested.Results showed that HNTs were successfully grafted and modified, and the HNTs/SiO2 composite aerogel exhibited a porous structure, creating a micro - and nanoscale hierarchical rough structure.When the HNTs content was 25%(mass fraction), the resulting coating had a water contact angle of 160.8°, a rolling angle of 3.1°, and a thermal conductivity of 0.045 W/(m·K).After 20 wear cycles, the water contact angle remained at 152.5°,indicating its applicability to various soft and hard substrates.
  • MAO Ruirui, ZHANG Jie, BIAN Yafei, ZHAO Qian, MIAO Chunhui, CHEN Guohong, TANG Wenming
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    In order to explore the correlation between soil texture, soil physicochemical properties, and the soil corrosion rate of galvanized steel, galvanized steel specimens buried in the natural soil environment of representative substation sites in Anhui Province for one year were selected.The composition and structure of the corrosion layer were studied, and the soil corrosion mechanism was investigated.Soil corrosion rate data were obtained, with the help of Spearman correlation analysis, the influence of key soil physicochemical properties on the soil corrosion of galvanized steel specimens after one year was studied.Finally,electrochemical characteristics of galvanized steel specimens were studied in simulated soil corrosion solutions with different pH values and salt concentrations.Results showed that in the soil environment of Anhui Province, the corrosion products on the surface of the galvanized layer exhibited significant stratification, with characteristics of uneven general corrosion.Soil particles embedded in the corrosion layer exacerbated localized corrosion of the galvanized layer.The corrosion products were mainly composed of ZnO,Zn(OH)2,Zn5(OH)6(CO3)2,and Zn4(OH)6SO4.The ranking of correlations between the soil corrosion rate of galvanized steel specimens after one year and soil texture and physicochemical properties in Anhui Province was as follows:pH value>salt content >redox potential >moisture content >soil resistivity >soil texture.Electrochemical test results also showed that the pH value had a greater effect on the corrosion current density (Jcorr) of the galvanized steel specimens than chloride ion concentration, which verified the accuracy of the Spearman correlation analysis.
  • LI Jun, YU Yanzhao, ZHU Hongzhang, YU Xiaohong, LEI Bo, CHEN Changfeng
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    During oil extraction,the corrosion of oil pipes caused by chloride-containing completion fluids has been a hot research topic.To address this problem, the stress corrosion cracking (SCC) sensitivity of Super 13Cr stainless steel was investigated under simulated downhole conditions (130 ℃, total pressure 40 MPa) in chloride-containing completion fluids with different concentrations (0, 1.15, 1.25 g/cm3).A combined method of four-point bending and slow strain rate testing (SSRT) was used to evaluate the material’s performance, and fracture analysis was conducted using scanning electron microscopy (SEM).Results showed that in the chloride-containing completion fluid environment, Super 13Cr stainless steel exhibited a certain degree of stress corrosion sensitivity.The four-point bending results showed that with the increase in chloride concentration,corrosion of the material intensified,fracture toughness decreased,and SCC sensitivity increased.The SSRT results showed that the SCC sensitivity of Super 13Cr stainless steel in the completion fluids with three concentrations was ranked as follows: 0 g/cm3<1.15 g/cm3<1.25 g/cm3.The stress corrosion cracking mechanism of Super 13Cr stainless steel in high-temperature, high-pressure chloride-containing completion fluid was anodic dissolution-type SCC, and the increased chloride ion concentration accelerated the dissolution of the passive film and promoted the occurrence of localized corrosion.