Surface & Coatings Technology最新文献

{"title":"Microstructure and dielectric properties of Al₂O₃–Cr₂O₃ composite coatings fabricated by wide-velocity range high-energy plasma spraying","authors":"Y.Z. Zhang ,&nbsp;J.H. Zu ,&nbsp;Y. Wang ,&nbsp;M. Liu ,&nbsp;H.D. Wang ,&nbsp;Y. Bai","doi":"10.1016/j.surfcoat.2025.132423","DOIUrl":"10.1016/j.surfcoat.2025.132423","url":null,"abstract":"<div><div>The presence of γ-phase in alumina (Al₂O₃) coatings has been widely acknowledged as a detrimental factor compromising dielectric performance, presenting a longstanding challenge in advanced coating design. To overcome this limitation, a series of Al₂O₃-Cr₂O₃ composite coatings were fabricated by wide-velocity range high-energy plasma spraying (WPS) in this study. The systematic investigation of chromium oxide (Cr₂O₃) doping effects on dielectric properties of as-sprayed coatings was conducted through dielectric breakdown tests. The results suggested that the incorporation of Cr₂O₃ effectively reduced porosity and increased α-Al₂O₃ content in all the as-sprayed coatings. Compared to pure Al₂O₃ coatings, the Al₂O₃-Cr₂O₃ composite coatings exhibited significantly lower porosity and higher α-Al₂O₃ content. There is a marked decrease of porosity (1.3–1.7 %) occurred when the Cr₂O₃ concentration increased to 4 % and 8 %. Notably, the α-Al₂O₃ content reached a maximum of 53.2 % at 4 wt% Cr₂O₃ incorporation, while the coating with 8 wt% Cr₂O₃ showed the highest breakdown voltage (35.2 V/μm), representing a 7.8 V/μm improvement (28.5 % increase from 27.4 V/μm for pure Al₂O₃) due to its high α-Al₂O₃ content and low porosity (4 %). Although various studies have addressed the retention of the α-Al₂O₃ in thermally sprayed Al₂O₃ coatings, achieving a balance between the α-Al₂O₃ and porosity remains a crucial challenge. Our findings provide valuable insights for the development of high-performance plasma-sprayed Al₂O₃-based insulating coatings, offering a viable pathway to enhance dielectric properties through controlled phase composition and microstructure engineering simultaneously.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132423"},"PeriodicalIF":5.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bio-tribo-corrosion behavior of additively manufactured Co-Cr dental implant alloy","authors":"N. Hashemi,&nbsp;Sh. Yahyavi,&nbsp;M. Moshkbar Bakhshayesh,&nbsp;F. Khodabakhshi,&nbsp;R. Mehdinavaz Aghdam","doi":"10.1016/j.surfcoat.2025.132422","DOIUrl":"10.1016/j.surfcoat.2025.132422","url":null,"abstract":"<div><div>A CoCr-based dental alloy was deposited upon layer built-ups through a laser-assisted directed energy deposition (L-DED) technique. Microstructural studies, including grain morphologies, crystallographic texture formation and nano planar defects were conducted utilizing advanced characterization techniques based on the scanning and transmission electron microscopies. Also, the biocompatibility and cell viability were evaluated with MG-63 cells via MTT assay and cell adhesion test. Additionally, mechanical properties of the deposited alloy, specifically hardness and wear resistance, were assessed through indentation micro-hardness measurements and tribological behavior examinations in simulated oral environments under different loading conditions. Finally, the resistance to corrosion was investigated in Ringer's solution by electrochemical techniques. Microstructural characterization revealed the formation of gradient structure along the building direction due to the combination of columnar/equiaxed dendritic morphologies upon rapid cooling, resulting in the generation of preferred 〈001〉 growth direction with a maximum misalignment of ~25° along scanning direction. In addition, the presence of dense stacking faults interacting with each other and carbides was identified as one of the key factors for strengthening, leading to a high average microhardness of 542 HV_0.2 and excellent wear resistance of around 4.2 × 10⁻⁵ mm³/N.m when subjected to a 50 N load. The remarkable viability of ~94.6 % for MG-63 cells cultured on the surface for a week, together with excellent cell spreading and adhesion, indicated the absence of any cytotoxic response. The high polarization resistance of ~650 kΩ.cm⁻² in simulated oral medium owing to the development of a mixed oxide layer suggested that the fabricated CoCr-based alloy was suitable for dental applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132422"},"PeriodicalIF":5.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polyethylene and polypropylene adsorption on Ti3C2Tx MXenes: a DFT study","authors":"Gabriel Gouveia Barbosa,&nbsp;João Pedro Vieira Garlippe,&nbsp;Suel Eric Vidotti,&nbsp;Anne Cristine Chinellato,&nbsp;Sydney Ferreira Santos,&nbsp;Roberto Gomes de Aguiar Veiga","doi":"10.1016/j.surfcoat.2025.132424","DOIUrl":"10.1016/j.surfcoat.2025.132424","url":null,"abstract":"<div><div>Polyolefins form a large class of polymers extensively used in industry. An approach to improve the properties of polyolefins to expand their applications is the incorporation of nanofillers. A new and promising family of nanofillers with potential to produce polyolefin-based nanocomposites with enhanced properties are MXenes, which comprise 2D transition-metal carbides and/or nitrides. In this work, a comprehensive series of Density Functional Theory (DFT) calculations was conducted to examine the interaction of the two most widely used polyolefins, polyethylene (PE) and polypropylene (PP), with Ti₃C₂T_x MXenes (T_x = O₂, F₂, S₂, Cl₂, and (OH)₂). The model systems consisted of single chains of either PE or PP adsorbed on the MXene surface in different configurations. The polymer-MXene binding energies, calculated as a function of MXene terminations, revealed that both polymers adhered more strongly to the O₂-terminated MXene, while adsorption on Ti₃C₂(OH)₂ was the weakest. In all cases, the relatively large polymer/MXene separation (ranging from 2.2 to almost 3 Å) implies that weak interactions (van der Waals with a hydrogen bonding component) predominate. It is also observed that PE/MXene binding energies were much higher than those of PP/MXene, thus indicating stronger interfacial adhesion is expected in PE/MXene composites. Consistent with the overall weak nature of the polymer/MXene interaction, electronic structure analysis shows that the metallic character of MXene was preserved regardless of surface termination or adsorbed polymer.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132424"},"PeriodicalIF":5.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-healing superhydrophilic polyurea composite coating for durable oil/water separation","authors":"Jinlong Wu ,&nbsp;Peng Wang ,&nbsp;Yukun Tian ,&nbsp;Shan Liang ,&nbsp;Wenbiao Zhang ,&nbsp;Xiaoyan He ,&nbsp;Qianqian Li ,&nbsp;Jianghua Du","doi":"10.1016/j.surfcoat.2025.132416","DOIUrl":"10.1016/j.surfcoat.2025.132416","url":null,"abstract":"<div><div>Oil/water separation membranes are prone to damage from environment, which limits their application in treating oily wastewater. Improving the durability of these membranes remains challenging. In this study, we incorporated robust polyurea (PU) into a coating. The structure of polyurea was modulated to introduce multiple hydrogen bonds and dynamic disulfide bonds, thus affording a polyurea coating with 90.53 % self-healing efficiency at 80 °C. The disulfide bonds imparted self-healing properties to the coating, while the multiple hydrogen bonds enhanced its stability. Phytic acid (PA), a natural product, and polyethyleneimine (PEI), a positronic compound, were synergistically combined with the polyurea coating to increased hydrophilicity through hydrogen bonding, coordination chelation, and electrostatic interactions. PEI/PA/SHPU@SSM was obtained by applying the composite coating to a stainless steel mesh surface. After 32 oil/water separation cycles, the self-healing group maintained a separation efficiency of 97.6 %, outperforming the non-self-healing group by 1.3 %. After 30 abrasion cycles, the underwater oil contact angle of the self-healing group was 147.1°, which was 6.5° higher than that of the non-self-healing group. The results highlight the effectiveness of the self-healing in enhancing the oil/water separation durability of PEI/PA/SHPU@SSM. This study offers new insights for improving the durability of superhydrophilic coating materials.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132416"},"PeriodicalIF":5.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of real-time thermal signatures and Scheil simulation for track geometry, microstructure, and phase formation in LMD of NiCoCrAlY for gas-turbine components","authors":"Saikat Nandi ,&nbsp;Prasenjit Patra ,&nbsp;Saurav Misra ,&nbsp;Ipsita Mohanty ,&nbsp;Partha Saha ,&nbsp;Pranab K. Dan","doi":"10.1016/j.surfcoat.2025.132421","DOIUrl":"10.1016/j.surfcoat.2025.132421","url":null,"abstract":"<div><div>This study presents an integrated approach combining real-time process temperature monitoring and Scheil-based CALPHAD simulations to investigate the process–structure–property relationship in laser metal deposition (LMD) of NiCoCrAlY tracks on an Inconel 718 substrate, aimed at gas turbine applications. Real-time thermal signatures captured by an IR pyrometer were analyzed to correlate those with track geometry, microstructure, phase formation, and mechanical properties. Concurrently, Scheil-based CALPHAD simulations, validated through XRD and Rietveld refinement, were used to predict phase evolution based on compositional changes induced by varying process parameters. The β-NiAl (BCC) and γ-Ni (FCC) phases were identified as dominant constituents, with their relative proportions highly sensitive to dilution, governed primarily by scan speed rather than power. Increased scan speed led to greater dilution and higher γ-Ni fraction, reducing β-NiAl content from 58 % to 14 %, which directly correlated with a drop in microhardness from 510 to 346 HVN₀.₂. Thermal analysis revealed that melt pool life and peak temperature, rather than cooling rate, exhibited a strong correlation with resulting mechanical properties. A longer melt pool life (180–230 ms) and a peak temperature around 1940–2000 °C are attributed to β-dominated microstructures with enhanced hardness. The optimized track, produced at 800 W and 600 mm/min, demonstrated a scratch hardness of 2.85 ± 0.22 GPa, more than twice that of the substrate, indicating superior wear resistance. This study highlights that combining thermal signature analysis with Scheil simulation provides a reliable predictive framework for controlling phases and mechanical properties in LMD of NiCoCrAlY coatings.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132421"},"PeriodicalIF":5.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure and oxidation behavior of a laser-deposition WTaNbMo/γ-(Ni, Cr) refractory high-entropy alloy coating with dynamic magnetic field assistance","authors":"Yue Zhao ,&nbsp;Qiaoqing Jin ,&nbsp;Yihui Lv ,&nbsp;Lin Cai ,&nbsp;Na Su ,&nbsp;Ruifeng Li ,&nbsp;Ruimin Gao ,&nbsp;Tingting Zhang ,&nbsp;Jiangbo Cheng","doi":"10.1016/j.surfcoat.2025.132417","DOIUrl":"10.1016/j.surfcoat.2025.132417","url":null,"abstract":"<div><div>In this study, WTaNbMo/γ-(Ni, Cr) refractory high-entropy alloy composite coatings were successfully fabricated through magnetic field-assisted laser deposition. A comprehensive investigation was conducted to elucidate the effects of magnetic field on the microstructural evolution of the coatings. Magnetic field assistance effectively eliminated surface cracks, enhanced compositional homogeneity, and reduced texture (by 57.39 %) and grain size (by 79.19 %) in the laser-deposition composite coating. Furthermore, the influence of γ-(Ni, Cr) content on the high-temperature oxidation resistance was systematically examined from both thermodynamic and kinetic perspectives. The results demonstrated that increasing γ-(Ni, Cr) content progressively reduced oxide film thickness and improved high-temperature oxidation resistance. However, excessive γ-(Ni, Cr) content was found to substantially compromise the high-temperature hardness. The optimal balance of high-temperature properties and oxidation resistance was achieved at 62.26 % γ-(Ni, Cr) content, exhibiting a high-temperature hardness of 237.5 HV_0.5 and a 1000 °C 24-h oxidation weight gain of 6.923 mg/cm². The enhanced high-temperature oxidation resistance of the WTaNbMo/γ-(Ni, Cr) composite coatings is attributed to the formation of a dense protective oxide film Cr₂O₃/CrNbO₄/CrTaO₄. This multi-component oxide film effectively shields the composite from further oxidation, thereby significantly reducing the oxidation rate and improving the high-temperature performance.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132417"},"PeriodicalIF":5.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ag-containing refractory metal high-entropy nitride coatings with enhanced hardness, corrosion resistance, and antibacterial performance","authors":"Chuanyao Dong ,&nbsp;Zhixuan Mu ,&nbsp;Yiwei Li ,&nbsp;Linhe Lv ,&nbsp;Xinlei Gu ,&nbsp;Junhan Yao ,&nbsp;Xingfu Bao ,&nbsp;Xiaoxi Wei ,&nbsp;Kan Zhang","doi":"10.1016/j.surfcoat.2025.132420","DOIUrl":"10.1016/j.surfcoat.2025.132420","url":null,"abstract":"<div><div>Artificial temporomandibular joint (TMJ) replacement surgery effectively restores function and relieves pain in severe joint disorders. However, the complex physiological environment of the TMJ presents significant challenges, including persistent interfacial friction, severe corrosion, and bacterial adhesion, which critically limit implant longevity. This study introduces Ag into refractory metal nitrides based on the concept of high-entropy engineering, successfully synthesizing a stable single-phase solid solution (TiZrNbHfTaAg)N coating with 5.7 at.% Ag. This Ag-containing high-entropy coating exhibits excellent spontaneous oxidation capabilities, significantly enhancing antibacterial performance (antibacterial rate = 90.9 %) compared to both the Ag-free (TiZrNbHfTa)N coating and the Ag-agglomerated (TiZrNbHfTaAg)N/Ag coating. Furthermore, the high-entropy engineering approach mitigates the common issue of Ag agglomeration, which often compromises mechanical integrity and corrosion resistance of coatings. The solution strengthening effect substantially improves the mechanical properties (hardness = 26.06 ± 1.01 GPa) and wear resistance (wear rate = 1.83 × 10⁻⁶ mm³/Nm) of the (TiZrNbHfTaAg)N coating. Additionally, the (TiZrNbHfTaAg)N coating also demonstrates excellent corrosion resistance, with a corrosion current density of 1.2 × 10⁻⁷ A/cm². This innovative coating design effectively addresses the inherent limitations of current TMJ implants, providing a balanced enhancement of antibacterial performance, mechanical strength, and longevity, thereby advancing protective strategies for artificial joint implants.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132420"},"PeriodicalIF":5.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144330329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of nanoporous doped metal oxide coatings via selective infiltration of a block copolymer template: The case of Al-doped zinc oxide","authors":"Vasanta Gurung ,&nbsp;Khalil D. Omotosho ,&nbsp;Oluwatosin Obe ,&nbsp;Elena Shevchenko ,&nbsp;Diana Berman","doi":"10.1016/j.surfcoat.2025.132418","DOIUrl":"10.1016/j.surfcoat.2025.132418","url":null,"abstract":"<div><div>Conductive nanoporous conformal coatings are important for various applications including touchscreens, displays, and electrochromic windows, though design of such coating with controlled porosity and composition remains challenging. We propose a sequential infiltration synthesis (SIS) method for the fabrication of nanoporous conductive aluminum-doped zinc oxide (AZO) films by infiltrating block copolymer (BCP) templates, specifically polystyrene-<em>block</em>-polyvinyl pyridine (PS-b-P4VP), with diethyl zinc and trimethyl aluminum precursors. Tunability of both porosity and electrical conductivity is achieved by precisely controlling the swelling behavior of the polymer templates and adjusting the number of SIS cycles. Our results reveal that porosity levels can reach up to 80 %, with resistivity as low as ~7.83 Ωcm. Using conductive atomic force microscopy (C-AFM) and Hall effect measurements, we show that lower concentrations of aluminum doping relative to zinc (around 1: 17) results in higher conductivity of the AZO films. Additionally, AZO is based on zinc oxide (ZnO) which is cost-efficient, abundant and less toxic than commonly used transparent conductive oxides such as indium tin oxide (ITO) and fluorine-doped tin oxide (FTO). Therefore, this novel approach opens new possibilities for creating highly porous, conformal, conductive AZO coatings with customizable porosity and composition, making them ideal candidates for diverse optoelectronic applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132418"},"PeriodicalIF":5.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144366165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure and tribological properties of (AlCrTiV)Nx high-entropy alloy films prepared by magnetron sputtering","authors":"Lei Yan ,&nbsp;Sikai Mei ,&nbsp;Zhaobing Cai ,&nbsp;Ying Liu ,&nbsp;Bingxu Wang ,&nbsp;Le Gu","doi":"10.1016/j.surfcoat.2025.132406","DOIUrl":"10.1016/j.surfcoat.2025.132406","url":null,"abstract":"<div><div>High-entropy alloy (HEA) films of (AlCrTiV)N_x with varying N content were deposited on 316 substrates using magnetron sputtering technology. The aim is to examine the influence of N content on the microstructure, mechanical properties, and tribological performance of the films. Results reveal that the introduction of N facilitates the transformation of the films from an amorphous state to a single FCC phase structure. As the N₂ flow rate increases, a columnar crystal structure emerges in the film cross-section, accompanied by a decrease in film thickness and a reduction in grain size. During the experimentation, the four metal elements (Al, Cr, Ti, V) combine with N to form quaternary nitrides (Al, Cr, Ti, V)N, which alter the surface morphology and quality of the films, resulting in increased surface roughness. Following the introduction of N, the hardness and elastic modulus of the films are enhanced; however, both properties exhibit an overall decreasing trend with rising N content. The maximum values, recorded at the N₂ flow rate of 2 sccm, are 14.6 GPa for hardness and 298.5 GPa for elastic modulus. At this flow rate, the friction coefficient is 0.257, while the wear rate reaches its minimum value of 3.5 × 10⁻⁶ mm³/N·m, indicating optimal anti-friction and wear resistance performance. As the N₂ flow rate increases, the wear mechanism transitions from oxidative wear to a combination of oxidative and abrasive wear. Notably, Cr₂O₃ constitutes the largest proportion of the wear debris products, attributable to its strong oxidation properties.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132406"},"PeriodicalIF":5.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144366163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative study on the microstructure and mechanical properties of Ni625 alloy deposited by conventional and ultra-high-speed laser cladding for the repairing of EA4T railway axle steel","authors":"Dongdong Ji,&nbsp;Jiwang Zhang,&nbsp;Bo Zhang,&nbsp;Kaixin Su,&nbsp;Xingyu Chen,&nbsp;Renhui Li","doi":"10.1016/j.surfcoat.2025.132415","DOIUrl":"10.1016/j.surfcoat.2025.132415","url":null,"abstract":"<div><div>This study compares the microstructure and mechanical properties of Ni625 alloy coatings produced by conventional laser cladding (CLC) and ultra-high-speed laser cladding (UHSLC) for the repair of EA4T railway axle steel. The results demonstrate that the UHSLC process, characterized by lower heat input and faster cooling rates, significantly improves cladding efficiency and reduces the size of the heat-affected zone (HAZ) in the substrate compared to CLC under typical processing conditions. The UHSLC coating exhibits more uniform and finer grains, with a significantly lower dilution rate compared to the CLC specimen. The hardness of the UHSLC coating is higher, approximately 300 HV, compared to 275 HV for the CLC coating. In tensile testing, the ultimate tensile strength and yield strength of the UHSLC specimen are closer to the base material, and the fracture mode shows ductile-brittle mixed characteristics. In contrast, the CLC specimens are more prone to crack initiation at the coating-substrate interface, exhibiting higher brittleness and larger residual stresses. The UHSLC process demonstrates significant advantages over the CLC process by refining the grain structure, reducing the size of the HAZ, and lowering residual stresses. These benefits provide a theoretical foundation for the selection and optimization of parameters in subsequent modification processes for railway axle steel.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"512 ","pages":"Article 132415"},"PeriodicalIF":5.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144470600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}