Journal of Thermal Spray Technology最新文献

{"title":"Graphene-Reinforced WC-CoCr Coatings by High-Velocity Air Fuel Spraying: A Path to Superior Corrosion Protection","authors":"Ishee Prasad Kar,&nbsp;Santosh Kumar,&nbsp;Navneet K. Singh,&nbsp;Swati Sharma,&nbsp;Shailesh Mani Pandey,&nbsp;Anup Kumar Keshri","doi":"10.1007/s11666-025-02028-x","DOIUrl":"10.1007/s11666-025-02028-x","url":null,"abstract":"<div><p>The present study investigates the effect of graphene nanoplatelets (GNPs) on the microstructure and corrosion resistance of WC-CoCr coatings deposited via high-velocity air fuel (HVAF) spraying. The HVAF process effectively mitigated decarburization through its controlled lower combustion temperature. The addition of 1 wt.% and 2 wt.% GNPs markedly improved coating densification by filling nanoscale pores, thereby reducing porosity and achieving a relative density of 99.57% for WC-CoCr + 2G. The high thermal conductivity of GNPs enabled uniform heat dissipation during spraying, leading to a 9.7% reduction in crystallite size, and a 25.6% decrease in lattice strain. Electrochemical studies in 3.5 wt.% NaCl solution revealed a remarkable reduction in the corrosion rate, dropping from 4.27 × 10^–6 mpy for WC-CoCr to 1.71 × 10^–8 mpy for WC-CoCr + 2G, demonstrating an almost 99% improvement. The enhanced corrosion resistance is attributed to GNPs acting as a diffusion barrier against Cl⁻ and Na⁺ ions while simultaneously catalyzing the rapid formation of a protective Cr₂O₃ passivation layer. This novel insight into the functional role of GNPs in tuning microstructure, strain relaxation, and electrochemical stability establishes HVAF-sprayed GNP-reinforced WC-CoCr coatings as a transformative solution for high-performance corrosion protection in aggressive environments.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2094 - 2107"},"PeriodicalIF":3.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Influence of Macroscopic Curvature on the Interface Strength and Life for Thermal Barrier Coatings","authors":"Peng Guan,&nbsp;Chengwei Wu,&nbsp;Bo Guan,&nbsp;Yanting Ai,&nbsp;Yudong Yao","doi":"10.1007/s11666-025-02014-3","DOIUrl":"10.1007/s11666-025-02014-3","url":null,"abstract":"<div><p>Thermal barrier coatings (TBCs) represent an effective technical approach for augmenting the high-temperature resistance of turbine blades. The microscopic interfacial characteristics of TBCs are directly influenced by the macroscopic structural configuration and mechanical loading conditions of turbine blades. Elucidating the correlation between macroscopic curvature and interfacial strength evolution in TBCs substantially improves the predictive accuracy of thermal fatigue life estimation. In this work, a stress-driven predictive model for TBCs thermal fatigue life is established through combining phenomenological and S-N curve methods with an oxide layer growth model. The master–slave method is implemented to analyze the influence of macroscopic curvature on the interface stress of TBCs. It is demonstrated that both equivalent stress and maximum shear stress at the interface are found to increase as the curvature of TC-layer decreases, whereas maximum principal stress exhibits limited sensitivity to macroscopic curvature variations. The comparison between predictive outcomes and experimental measurements is revealed to exhibit a 32.89% deviation in thermal fatigue life estimation. Moreover, a significant reduction in coating thermal fatigue life is identified with decrease in macroscopic curvature. These findings are validated through correlation with failure characteristics observed in serviced turbine blade TBCs, thereby substantiating the proposed conclusions. The developed predictive framework is established as a valuable reference for the design of high-performance turbine blade systems incorporating TBCs.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2470 - 2482"},"PeriodicalIF":3.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the Fuel and High-Velocity Spray Technique on Corrosion and Antifouling Properties of Cu Coating","authors":"Jaqueline Garcia,&nbsp;Thayline Vaz,&nbsp;Elisabete Hiromi Hashimoto,&nbsp;Simone do Rocio Ferraz Sabino,&nbsp;Edson Cezar Grzebielucka,&nbsp;Irene Bida de Araújo Fernandes Siqueira,&nbsp;Rodolpho Fernando Vaz,&nbsp;Irene Garcia Cano,&nbsp;Anderson Geraldo Marenda Pukasiewicz","doi":"10.1007/s11666-025-02027-y","DOIUrl":"10.1007/s11666-025-02027-y","url":null,"abstract":"<div><p>Metallic surfaces exposed to natural or marine water are susceptible to the adhesion of living microorganisms, a process called biofouling. Different thermal spraying processes, especially the high kinetic energy ones, can be used to face the challenges of distinct types of material wear. This work deposited pure Cu coatings using different variations of high-velocity oxy-fuel (HVOF): propane, kerosene, and ethanol fuel, and compared to 304SS and Cu deposited by high-pressure cold spray (CS). The samples were characterized by OM, SEM, XRD. Corrosion properties were measured during electrochemical tests in NaCl solution. Biofouling test conducted with <i>Pseudomonas aeruginosa</i> pathogen was cultured to prepare the challenge suspension and then applied on each replicate for 21 days in a Time-Kill assay. The HVOF-propane splats were less deformed than HVOF-ethanol ones, and the HVOF-kerosene promoted the highest microhardness among the samples due to its higher oxide content. The HVOF-propane coating has the lowest count in the biofilm formation test, followed by the HVOF-ethanol. All HVOF Cu coatings had a better antifouling performance than the 304SS reference.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2458 - 2469"},"PeriodicalIF":3.3,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on High-Temperature Oxidation Behavior and Mechanism of La2O3-Modified Hastelloy-C22 Coatings by Laser Cladding","authors":"Siyi Qi,&nbsp;Zhaohui Wang,&nbsp;Lincong Li,&nbsp;Xuming Wu,&nbsp;Shubo Li,&nbsp;Wenbo Du","doi":"10.1007/s11666-025-02026-z","DOIUrl":"10.1007/s11666-025-02026-z","url":null,"abstract":"<div><p>In this study, the high-temperature oxidation behavior and mechanism of Hastelloy-C22 coatings modified with La₂O₃ by laser cladding were systematically investigated. The microstructural morphology and oxidation product characteristics of the coatings were characterized through various analytical methods, including scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), x-ray diffraction (XRD), and laser confocal microscopy. The results indicate that La₂O₃ particles are primarily distributed along the grain boundaries of the coating, facilitating the entry of a solid solution of Cr, Mo, and Co into the γ-Ni lattice during the cladding process. With increasing La₂O₃ content, the content of the Ni-Cr-Co-Mo phases in the coating also increased. In the temperature range of 700-900 °C, the average thickness of the oxide layer of the coating with 1 wt.% La₂O₃ was reduced by 37%. After the addition of La₂O₃, the coating formed a La₄MoO₉ phase upon high-temperature oxidation. This phase effectively protects the metallic elements within the coating from oxidative attack, such as Ni, Cr, and Fe, resulting in optimal oxidation resistance for the coating. Furthermore, as the oxidation temperature increased, the mass of the C22-xLa₂O₃ coating gradually increased, displaying a parabolic relationship with the duration of oxidation.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2309 - 2325"},"PeriodicalIF":3.3,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cold Spraying Remanufacturing Repair of Carbon Fiber-Reinforced Polyether Ether Ketone Composites","authors":"Huanbo Cheng,&nbsp;He Zhai,&nbsp;Lijun Guo,&nbsp;Mingxi Tang,&nbsp;Zhengchun Qian","doi":"10.1007/s11666-025-02018-z","DOIUrl":"10.1007/s11666-025-02018-z","url":null,"abstract":"<div><p>To address the challenges of low efficiency and inconsistent quality in repairing carbon fiber-reinforced polymer (CFRP) components, a cold spraying remanufacturing repair process of CFRP was proposed. Using damaged carbon fiber-reinforced polyether ether ketone (CF-PEEK) as the study object, a finite element model of the Laval nozzle and substrate was developed in ANSYS FLUENT to conduct computational fluid dynamics analysis and determine optimal process parameters. Based on the simulation results, cold spray repair experiments were carried out. The performance of the repaired composites was evaluated through tensile strength testing, porosity measurements, and wear resistance testing. The finite element analysis indicated that the optimal experimental parameters were 473K and 1MPa, using repair particles with a size of 75 μm. The tensile strengths of pure polyether ether ketone and CF-PEEK repaired specimens were reached 91.3 and 93.3% of their non-destructive counterparts, respectively. Micro-morphology indicated that the repair layer was well bonded with the substrate, and the porosity and wear resistance were also relatively excellent. These findings demonstrate that cold spraying is a promising on-site repair technology for composite structures. This study provides both theoretical insight and technical guidance for achieving rapid and efficient on-site repair of composites. </p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2240 - 2255"},"PeriodicalIF":3.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145079043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights Into the Arrangement of Main Working Gas and Powder Carrier Gas on Gas–Particle Flow Dynamics in Cold Spraying","authors":"Wenpeng Wan,&nbsp;Chunjie Huang,&nbsp;Jie Luo,&nbsp;Zhengmao Zhang,&nbsp;Yaxin Xu,&nbsp;Wenya Li","doi":"10.1007/s11666-025-02024-1","DOIUrl":"10.1007/s11666-025-02024-1","url":null,"abstract":"<div><p>During cold spraying, the interaction between the powder carrier gas and the main working gas plays an important role in determining coating quality and deposition efficiency by influencing both gas flow dynamics and particle behavior. However, comparative studies examining the effects of different gas stream designs on gas flow fields and particle acceleration behaviors remain limited. In this study, three key configurations of the two gas streams—coaxial, 45° inclined, and perpendicular—are systematically analyzed through numerical modeling. The configuration of the two gas streams considerably affects the gas temperature distribution and particle acceleration behavior upstream of the spraying gun but exhibits minimal influence on the velocity field downstream and the particle impact area on the substrate. When the two gases are placed at a 45° angle, the preheating effect on the powder carrier gas and particles is optimal. However, this arrangement also leads to the most severe particle backflow, increasing the probability of particle–wall collisions, which in turn increases the risk of nozzle blockage. In comparison, when the gas streams are arranged perpendicular to each other, the particle backflow phenomenon and nozzle clogging risk drastically decrease, and this risk is further minimized when the two gases are coaxial. Therefore, for low-melting-point powders that are prone to nozzle clogging (such as aluminum), coaxial or perpendicular gas arrangements are recommended. For high-melting-point particles that are less likely to clog the nozzle (such as copper), a 45° gas arrangement is preferred to optimize particle impact temperature, thereby improving coating quality. The outcomes present valuable insights into the benefits and limitations of the three distinct arrangements between the powder carrier gas and the main working gas, broadening the understanding of their effects on particle deposition efficiency and coating quality.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2174 - 2189"},"PeriodicalIF":3.3,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovative Thermal Spray Deposition Techniques for Polymer and Polymeric Matrix Composite Substrates: Methodologies, Characteristics, and Real-World Applications","authors":"A. Rezzoug,&nbsp;R. B. Gholenji,&nbsp;M. Yandouzi","doi":"10.1007/s11666-025-02023-2","DOIUrl":"10.1007/s11666-025-02023-2","url":null,"abstract":"<div><p>The application of thermal spray (TS) coatings on polymers and polymer matrix composite substrates has recently attracted considerable scholarly interest, leading to the publication of numerous review articles that articulate the current advancements in the field. Nonetheless, most of these reviews have primarily concentrated on metallization methodologies, including cold spray (CS) and thin-film deposition techniques. Despite the widespread implementation of CS and metallic coatings, alternative TS methodologies, such as arc, plasma, and combustion-based spraying, along with various coating materials like ceramics, polymers, and composites, are similarly gaining prominence. This review offers a comprehensive analysis of various feedstock materials and TS techniques, with a particular focus on their compatibility with polymer-based substrates. The aim is to accomplish a wide array of augmented material characteristics while accentuating the unique attributes of each TS technique. Detailed discussion is provided on each TS process, including particle–substrate interactions, required preparation, interlayers, coating buildup, and bonding mechanisms. By synthesizing the available literature, this review presents a comprehensive overview of the historical development of TS technologies, outlining major innovative advancements. It seeks to elucidate researchers' contributions to addressing deposition mechanism challenges and to underscore the merits and limitations of each TS methodology. The coatings are analyzed in terms of the properties they impart to the substrate, with a focus on potential applications. Examples of practical applications in various fields, such as thermal protection, biomedical engineering, electrical engineering, and tribology, are presented. Furthermore, the review summarizes the challenges facing the development of these techniques as efficient treatments for P/PMC substrates provide guidelines for future research. Novel application domains are proposed based on the most recent research outcomes. Ultimately, this critique aspires to facilitate the selection of feedstock substances and spraying methodologies, taking into consideration the intended application.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2037 - 2080"},"PeriodicalIF":3.3,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of MoB2 Content on the Microstructure and Wear Resistance of NiCr Coatings by Laser Cladding","authors":"Zicong Zhang,&nbsp;Xudong Nie,&nbsp;Yuming Zhou,&nbsp;Hongyuan Su,&nbsp;Jinyong Xu,&nbsp;Sergi Dosta,&nbsp;Ga Zhang,&nbsp;Chao Zhang","doi":"10.1007/s11666-025-02021-4","DOIUrl":"10.1007/s11666-025-02021-4","url":null,"abstract":"<div><p>The aim of this study is to investigate the mechanism of the influence of different contents of ceramic-reinforced particles MoB₂ on the microstructure, microhardness, and wear resistance of NiCr coatings. The x (MoB₂)-NiCr composite coatings with varying MoB₂ contents (<i>x</i> = 0,1,5,10, and 15 wt%) were applied to 304 steel using laser cladding. The results suggest the composite coatings consist of γ-(Ni, Cr), γ-(Ni, Fe), Ni_2.9Cr_0.7Fe_0.36, and MoB₂. The hardness of the composite coatings gradually increased as the MoB₂ content increased. The highest average hardness of the composite coatings was achieved when 15 wt% MoB₂ was added, reaching 485.5HV_0.1, which was 61.5% higher than the NiCr coating without MoB₂. The wear resistance of the composite coatings exhibited an initial enhancement followed by a decrease with the MoB₂ content increased. The 10 wt% MoB₂-NiCr coating exhibited the highest wear resistance, and the wear rate decreased by 75.5% compared with the NiCr coating without MoB₂. The wear mechanism of the coatings changed from severe fatigue and adhesive wear to slight abrasive and oxidative wear with the increase of MoB₂.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2372 - 2386"},"PeriodicalIF":3.3,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tribological Behavior of Copper Coatings Deposited by HVAF and Cold Spray: A Comparative Assessment","authors":"Martin Asuquo,&nbsp;Golnoush Asadiankouhidehkordi,&nbsp;Yinyin Zhang,&nbsp;Christian Moreau,&nbsp;Pantcho Stoyanov","doi":"10.1007/s11666-025-02020-5","DOIUrl":"10.1007/s11666-025-02020-5","url":null,"abstract":"<div><p>This study aims to evaluate the tribological performance of copper coatings developed by high-velocity air fuel (HVAF) and cold spray (CS) which are two important low-temperature solid-state deposition processes among spraying techniques. Reciprocating sliding wear tests against alumina balls were conducted at room (25 °C) and high (300 °C) temperatures. HVAF and CS coatings showed similar friction coefficients, both with a greater friction at high temperature. However, they exhibited different wear behaviors, where HVAF coating showed increased wear depth with temperature raise, while wear depth of CS coatings remained similar. Ex situ characterizations performed from the top and cross section of the worn surfaces by SEM, EDX, and Raman spectroscopy indicated profound oxidation occurred inside the wear tracks and higher wear of HVAF coating at high temperature was mainly due to greater oxidation and more cracks inside the tribolayer.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2158 - 2173"},"PeriodicalIF":3.3,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact Wear Evolution Mechanism of Fe2Ni2CrV0.5Nb0.8 Eutectic High-Entropy Alloy Coating under Dynamic Cyclic Impacts","authors":"Yingying Li,&nbsp;Hao Liu,&nbsp;Wenqin Wang,&nbsp;Sining Pan,&nbsp;Peijian Chen,&nbsp;Xiuli He,&nbsp;Gang Yu","doi":"10.1007/s11666-025-02019-y","DOIUrl":"10.1007/s11666-025-02019-y","url":null,"abstract":"<div><p>The dynamic impact test of eutectic high-entropy alloy (EHEA) coating composed of alternating arrangement of soft and hard phases is employed to investigate the damage accumulation principles under impact cycles combined with microstructure characteristic. The Fe₂Ni₂CrV_0.5Nb_0.8 EHEA coating presents a typical hypoeutectic alloys structure with the lamellar eutectic colonies of Laves and FCC phase uniformly dispersed within the primary FCC solid solution matrix. The Laves phase, serving as the primary load-bearing constituent, provides exceptional deformation resistance, while the FCC phase accommodates plastic strain to mitigate stress concentration and suppress crack initiation. The coating undergoes plastic deformation during the initial stage (10–1000 cycles), and the impact wear volume increases slowly. The impact energy dissipation under impact loading is predominantly attributed to elastic–plastic deformation. The slight edge damage stage exceeding 5000 cycles is characterized by oxidative wear. The tangential shear force at the edge position induce material spalling and accelerating impact wear volume growth, progressively elevating energy loss via wear. As the impact cycles approaches 15000, the material exhausts its capacity for further plastic deformation, shifting energy dissipation predominantly to wear-driven mechanisms. The high residual stresses formed on the impact crater surface initiate microcracks, promoting oxide layer exfoliation. Fatigue wear governs the failure mechanism, accompanied by a sharp rise in wear rate due to cyclic stress-induced crack propagation.</p></div>","PeriodicalId":679,"journal":{"name":"Journal of Thermal Spray Technology","volume":"34 6","pages":"2428 - 2441"},"PeriodicalIF":3.3,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}