Surface & Coatings Technology最新文献_第4页

Cracking and microstructure formation in laser cladded Ni60 coatings fabricated by circular and annular lasers: a comparative study 圆形和环形激光熔覆Ni60涂层的开裂和微观结构形成：比较研究

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-28 DOI: 10.1016/j.surfcoat.2025.132219

Yuan Chen , Guoxiang Liu , Yuehua Ma , Jiaheng Jiang , Lin Yang , Lyuyuan Wang , Yanbing Guo

{"title":"Cracking and microstructure formation in laser cladded Ni60 coatings fabricated by circular and annular lasers: a comparative study","authors":"Yuan Chen , Guoxiang Liu , Yuehua Ma , Jiaheng Jiang , Lin Yang , Lyuyuan Wang , Yanbing Guo","doi":"10.1016/j.surfcoat.2025.132219","DOIUrl":"10.1016/j.surfcoat.2025.132219","url":null,"abstract":"<div><div>Laser cladding of Ni60 hard-facing coatings were fabricated using isogenous circular and annular laser beams. The microstructure and cracking susceptibility of these laser-deposited coatings were examined, along with the analysis of temperature and stress fields through finite element (FE) simulation. The comparative study showed that the coatings deposited by the annular laser, at laser power inputs ranging from1500 to 2000 W, exhibited significantly lower cracking susceptibility than those deposited by the circular laser. The FE simulation results reveled a more homogeneous molten pool temperature in the annular laser deposition over 1500 W, which resulted in a lower concentration of stress, lower volume fraction formation of chromium borides, higher volume fraction formation of chromium carbides. Additionally, a more dendritic growth pattern was observed, accompanied by an increase in crystal grain size, which in turn led to a refinement in the chromium carbides crystal dimensions and a decrease in the occurrence of grain boundary formation in annular laser deposited coatings. This structural arrangement attributed to a decrease in hardness and stress concentration, substantially depressing the cracking susceptibility. And therefore, cracking-free coating with acceptable hardness loss was successfully achieved using the annular laser at 2000 W laser power input.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132219"},"PeriodicalIF":5.3,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887102","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}

引用次数: 0

Insights on the pulsed-DC powder-pack boriding process: equivalent circuit modeling and electric field distribution in the powder mixture–steel system 脉冲直流粉末包渗硼过程的见解：粉末混合钢系统的等效电路建模和电场分布

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-27 DOI: 10.1016/j.surfcoat.2025.132217

M. Olivares-Luna , S. Jimenez-Corona , F.P. Espino-Cortés , J.L. Rosales-Lopez , L.E. Castillo-Vela , K.D. Chaparro-Pérez , I. Campos-Silva

{"title":"Insights on the pulsed-DC powder-pack boriding process: equivalent circuit modeling and electric field distribution in the powder mixture–steel system","authors":"M. Olivares-Luna , S. Jimenez-Corona , F.P. Espino-Cortés , J.L. Rosales-Lopez , L.E. Castillo-Vela , K.D. Chaparro-Pérez , I. Campos-Silva","doi":"10.1016/j.surfcoat.2025.132217","DOIUrl":"10.1016/j.surfcoat.2025.132217","url":null,"abstract":"<div><div>This study presents a novel equivalent circuit model that incorporates a network of resistances in both series and parallel configurations to describe the electrical resistance behavior of the powder mixture-AISI 1018 steel system during pulsed-DC powder-pack boriding (PDCPB). The system was divided into volumetric blocks to represent the electrical characteristics of different powder mixture regions containing square steel samples of varying surface areas. For a powder mixture composition of 70 % B<sub>4</sub>C, 20 % SiC, and 10 % KBF<sub>4</sub>, the electrical resistivity remained consistent across different steel dimensions and volumetric block sizes, yielding a value of 1.6 Ωm with an error margin of no more than 7 % compared to experimental data.</div><div>Furthermore, finite element simulations revealed that the magnitude of the electric field during PDCPB is critical for maintaining uniform FeB-Fe<sub>2</sub>B layer growth. Variations in steel dimensions influenced the final boride layer thickness, corresponding to current densities of 558 mA cm<sup>−2</sup>, 361 mA cm<sup>−2</sup>, and 263 mA cm<sup>−2</sup>, respectively. The highest current density facilitated a greater B<sup>+</sup> concentration, enhancing boride layer formation. Finally, these findings provide valuable insights for predicting the electrical behavior of various powder mixture-material systems before PDCPB, facilitating process optimization for improved boride layer formation.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132217"},"PeriodicalIF":5.3,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895364","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}

引用次数: 0

Acoustic emission and surface modification of additively manufactured Ti-6Al-4V coupons during plasma electrolytic polishing using pulsed voltage 脉冲电压等离子体电解抛光过程中增材制造Ti-6Al-4V片的声发射和表面修饰

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-25 DOI: 10.1016/j.surfcoat.2025.132215

Yee Ng , Xian Yi Tan , Lei Zhang , Zi Wen Tham , Hui Ru Tan , Tzee Luai Meng , Chen-Nan Sun , Zhaohong Huang , Ming Lin , Hongfei Liu

{"title":"Acoustic emission and surface modification of additively manufactured Ti-6Al-4V coupons during plasma electrolytic polishing using pulsed voltage","authors":"Yee Ng , Xian Yi Tan , Lei Zhang , Zi Wen Tham , Hui Ru Tan , Tzee Luai Meng , Chen-Nan Sun , Zhaohong Huang , Ming Lin , Hongfei Liu","doi":"10.1016/j.surfcoat.2025.132215","DOIUrl":"10.1016/j.surfcoat.2025.132215","url":null,"abstract":"<div><div>Square-pulsed voltage with a peak value of 300 V and a duty cycle of 50 % was applied for plasma electrolytic polishing (PEP) at the plasma initiation-transition stage to address the effect of pulse frequencies, ranging from 500 to 2000 Hz, on acoustic emission (AE) and surface integrity modification of additively manufactured Ti-6Al-4V coupons. In-situ measurements revealed strong correlations between the current density and AE count, not only as a function of process time <em>t</em> but also with the frequency variations. A transition point, <em>t</em><sub>tr</sub>, has been observed. Both the current density and AE count decreased with <em>t</em> at <em>t</em> < <em>t</em><sub>tr</sub> and increased at <em>t</em> > <em>t</em><sub>tr</sub>. The <em>t</em><sub>tr</sub> increased with the increase in the frequency. However, the electrolyte temperature monotonically increased with <em>t</em> and decreased with the increase in voltage frequency. Surface characterizations revealed effective particle removal alongside pressure wave shock-peening and integrity modifications induced by the PEP process. The effect of peening increased with the increase in the pulse frequency, which strongly correlated with the acoustic amplitudes during the PEP process. These observations, compared to those resulted from constant-voltage PEP process (working at the traditional stable stage), provide evidence for enhanced mechanical effects but weakened electrochemical reactions induced by employing the pulsed-voltage.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132215"},"PeriodicalIF":5.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874733","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}

引用次数: 0

Trivalent cerium-doped zinc phosphate composite coating: A novel solution to the wear-corrosion coupling issue 三价铈掺杂磷酸锌复合涂层：一种解决磨损-腐蚀耦合问题的新方法

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-25 DOI: 10.1016/j.surfcoat.2025.132213

Qiwei Ma , Yanjun Ma , Dingjun Zhang , Jiaqi Yan , Lei Chen , Huidi Zhou , Jianmin Chen

{"title":"Trivalent cerium-doped zinc phosphate composite coating: A novel solution to the wear-corrosion coupling issue","authors":"Qiwei Ma , Yanjun Ma , Dingjun Zhang , Jiaqi Yan , Lei Chen , Huidi Zhou , Jianmin Chen","doi":"10.1016/j.surfcoat.2025.132213","DOIUrl":"10.1016/j.surfcoat.2025.132213","url":null,"abstract":"<div><div>A novel cerium-doped zinc phosphate (Ce-ZP) composite coating was developed to enhance corrosion resistance and tribological performance in marine environments. XRD, XPS, IR, and Raman spectroscopy confirmed successful cerium incorporation into the Zn<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> lattice, while ESEM and EDS analyses demonstrated a uniform microstructure. The Ce-ZP composite, incorporated into an epoxy-phenolic-PTFE matrix, exhibited low friction, high wear resistance, and superior corrosion protection. Electrochemical studies revealed a synergistic effect between Ce<sup>3+</sup> and Zn<sup>2+</sup>, forming passivation films that prolonged the coating’s lifespan. Compared to traditional zinc phosphate inhibitors, Ce-ZP demonstrated faster activation, improved durability, and enhanced stability. The tribological analysis confirmed that PTFE provided lubrication, Ce-ZP reinforced mechanical strength, and the synergistic corrosion-wear resistance mitigated wear-corrosion coupling damage. These findings indicate that Ce-ZP coatings offer a promising solution for high-salinity and corrosive marine environments.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132213"},"PeriodicalIF":5.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895363","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}

引用次数: 0

Evaluation of high-throughput columnar YSZ thermal barrier coatings deposited via axial plasma spraying of aqueous solution precursors 轴向等离子喷涂水溶液前驱体制备高通量柱状YSZ热障涂层的研究

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-25 DOI: 10.1016/j.surfcoat.2025.132214

Thomas Hervy , Rahul Jude Alroy , Stefan Björklund , Yiming Yao , Romain Genois , Shrikant Joshi

{"title":"Evaluation of high-throughput columnar YSZ thermal barrier coatings deposited via axial plasma spraying of aqueous solution precursors","authors":"Thomas Hervy , Rahul Jude Alroy , Stefan Björklund , Yiming Yao , Romain Genois , Shrikant Joshi","doi":"10.1016/j.surfcoat.2025.132214","DOIUrl":"10.1016/j.surfcoat.2025.132214","url":null,"abstract":"<div><div>Yttria stabilized zirconia (YSZ) coatings with a columnar microstructure are desirable in gas turbine engine applications as they impart enhanced thermal cyclic fatigue (TCF) life to thermal barrier coatings (TBCs) to extend their durability under extreme conditions. Traditionally deposited via electron beam physical vapor deposition (EB-PVD), such columnar coatings have also been successfully deposited by suspension plasma spraying (SPS). However, the flammability of ethanol-based suspensions typically used to obtain columnar coatings by SPS has limited broader adoption of the latter. This study comprehensively investigates the recently reported use of aqueous solution precursors to deposit columnar TBCs by axial plasma spraying. One of the objectives is to establish a robust parametric window that enables the deposition of columnar TBCs via axial solution precursor plasma spraying (SPPS). The resulting coatings have been characterized via microstructural, phase (XRD, EBSD) and microhardness analysis. Furthermore, the erosion resistance and TCF life of these coatings have also been evaluated, accompanied by post-failure analysis to investigate the failure mechanisms. A comparison with the reported performance of SPS-deposited TBCs suggests that axial plasma spraying of powder-free aqueous solution precursors presents a potentially promising alternative to obtain columnar coatings with attractive throughputs for industrial applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132214"},"PeriodicalIF":5.3,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882110","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}

引用次数: 0

Enhancement of the corrosion properties by alloying ternary TiAlN coatings with MgGd 用MgGd合金化三元TiAlN涂层增强腐蚀性能

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-24 DOI: 10.1016/j.surfcoat.2025.132210

Thomas Ulrich , Holger Hoche , Peter Polcik , Peter Kaestner , Matthias Oechsner

{"title":"Enhancement of the corrosion properties by alloying ternary TiAlN coatings with MgGd","authors":"Thomas Ulrich , Holger Hoche , Peter Polcik , Peter Kaestner , Matthias Oechsner","doi":"10.1016/j.surfcoat.2025.132210","DOIUrl":"10.1016/j.surfcoat.2025.132210","url":null,"abstract":"<div><div>This study investigates the corrosion resistance of novel PVD coatings by alloying TiAlN with MgGd. In previous work, MgGd alloying of TiN resulted in outstanding corrosion resistance of up to 1000 h in neutral salt spray (NSS) testing and improved performance in alkaline environments. The corrosion protection was attributed to a combination of hydrophobic surface effects, chemically inert passivation layers, and defect tolerance. To build on these findings, this study extends the alloying concept to ternary TiAlN-based systems. TiAlMgGdN coatings with varying Al/Mg ratios were synthesized and compared with a TiMgGdN reference to evaluate the influence of Al on microstructure, mechanical properties, and corrosion behavior. Characterization was performed using SEM, XRD, and XPS. The chemical composition was determined via GDOES and EDX. Corrosion properties were assessed under neutral, alkaline, and acidic conditions with NSS and potentiodynamic testing. Increasing the Al content led to a reduction in average crystallite size from 15.2 nm to 4.8 nm and an increase in coating hardness from 13.5 GPa to 18.5 GPa. Corrosion potential shifted by +129.7 mV in acidic and +68.9 mV in alkaline media for TiAlMgGdN relative to TiMgGdN. Despite a higher defect density (284 defects/mm vs. 171 defects/mm) and the more noble character, the Al-containing coatings demonstrated superior corrosion resistance. This is attributed to the formation of a chemically stable and protective Al<sub>2</sub>O<sub>3</sub> passivation layer that compensates for structural imperfections and limits the ingress of corrosive species. The novelty of this work lies in the first application of the MgGd alloying concept to a TiAlN matrix, demonstrating that the synergistic effects of Al and rare-earth elements significantly enhance both corrosion protection and mechanical performance, particularly in aggressive environments.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132210"},"PeriodicalIF":5.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874737","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}

引用次数: 0

Post-processing of laser-directed energy deposited IN718 superalloys through combined heat treatment and shot peening: Microstructural evolution and wear resistance enhancement 激光定向能沉积IN718高温合金复合热处理和喷丸强化后处理：显微组织演变和耐磨性增强

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-23 DOI: 10.1016/j.surfcoat.2025.132209

Mengyang Li , Xiaofeng Dang , Lingzhi Ning , Dingrui Liu , Yefei Geng , Fangyuan Cheng , Jianyong Dong , Ruiyao Liang , Zeng Tian , Guangni Zhou , Ting Guo , Yao Li

{"title":"Post-processing of laser-directed energy deposited IN718 superalloys through combined heat treatment and shot peening: Microstructural evolution and wear resistance enhancement","authors":"Mengyang Li , Xiaofeng Dang , Lingzhi Ning , Dingrui Liu , Yefei Geng , Fangyuan Cheng , Jianyong Dong , Ruiyao Liang , Zeng Tian , Guangni Zhou , Ting Guo , Yao Li","doi":"10.1016/j.surfcoat.2025.132209","DOIUrl":"10.1016/j.surfcoat.2025.132209","url":null,"abstract":"<div><div>While the laser-directed energy deposition (LDED) technique is extensively employed for repairing and fabricating complex components, LDED-fabricated IN718 superalloys parts frequently exhibit inadequate wear resistance. This study systematically investigates the combination effects of heat treatment strategies (<em>i.e.</em>, direct double aging (DA) and solution + double aging (SDA) treatments) and shot peening (SP) on the microstructural evolution and 600 °C wear performance of LDED-fabricated IN718 alloys. The aging regime promotes the complete precipitation of γ″/γ′ phases, while the prior solution treatment in the SDA process achieves concurrent dissolution of most Laves phases and partial recrystallization. SP converts surface tensile stress into compressive stress, reaching –1030.67 MPa in SDA + SP. Additionally, SP induces a work-hardened layer with a depth of ∼ 250 μm and a ∼ 500 nm thick nanograin layer at the topmost surface. The grain nanocrystallization is attributed to the simultaneous action of dislocations, twins, stacking faults, and Lomer-Cottrell (L-C) locks. The synergistic effects of grain refinement, work hardening, and γ″/γ′ precipitation collectively endow the SDA + SP sample with optimal sliding wear performance at 600 °C, exhibiting a 14.8 % reduction in average coefficient of friction and a remarkable 78.9 % decrease in wear rate compared to the as-received sample. This performance enhancement correlates with a transition in wear mechanisms to predominantly abrasive and oxidation-dominated regimes under elevated temperature conditions.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132209"},"PeriodicalIF":5.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882790","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}

引用次数: 0

Effect of Si and Cr on formation of aluminide coatings on Ti6Al4V alloy by low temperature aluminizing: Wear and oxidation behavior Si和Cr对低温渗铝Ti6Al4V合金铝化物涂层形成的影响：磨损和氧化行为

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-23 DOI: 10.1016/j.surfcoat.2025.132207

Kadir Mert Doleker , Tuba Yener , Azmi Erdogan , Ferhat Yılmaz , Gözde Celebi Efe

{"title":"Effect of Si and Cr on formation of aluminide coatings on Ti6Al4V alloy by low temperature aluminizing: Wear and oxidation behavior","authors":"Kadir Mert Doleker , Tuba Yener , Azmi Erdogan , Ferhat Yılmaz , Gözde Celebi Efe","doi":"10.1016/j.surfcoat.2025.132207","DOIUrl":"10.1016/j.surfcoat.2025.132207","url":null,"abstract":"<div><div>To improve the surface properties of the Ti-6Al-4 V titanium alloy, TiAl<sub>3</sub>-based intermetallic coatings were produced at 710 °C-4 h via a low-temperature aluminizing process. Additionally, Si and Cr were incorporated into the Ti<img>Al coating to investigate their effects on the properties of the Ti<img>Al system. The findings revealed that the coatings formed strong metallurgical bonds with the substrate, and no significant cracks were detected in the Ti<img>Al system coatings. However, the addition of Cr was found to have a negative effect on the growth of the coating layer. Similarly, the simultaneous addition of Cr and Si reduced the thickness of the layer from 14 μm to 5 μm. An increase of up to 248 GPa elastic modulus (E<sub>IT</sub>) and 10.36 GPa hardness was achieved with the aluminide coating of Ti6Al4V, which have had 150 GPa E<sub>IT</sub> and 5.56 GPa hardness. While all coatings provided better wear performance compared to the substrate, the lowest volume loss was observed in the TiAl coating with the highest thickness. Similarly, the best oxidation resistance was obtained in TiAl due to higher coating thickness and lower phase transformation in its coating layer compared to others. The addition of Si and Cr did not affect the formed oxide products, but they decreased the oxidation resistance due to thinner coating structure.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132207"},"PeriodicalIF":5.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869801","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}

引用次数: 0

Microstructure and wear resistance of environmentally friendly NbC-FeCr coatings: An evaluation of HVOF process parameters 环境友好型NbC-FeCr涂层的微观结构和耐磨性：HVOF工艺参数的评价

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-23 DOI: 10.1016/j.surfcoat.2025.132208

Lukas Tegelkamp , Maximilian Grimm , Susan Conze , Lutz-Michael Berger , Thomas Lindner , Thomas Lampke

{"title":"Microstructure and wear resistance of environmentally friendly NbC-FeCr coatings: An evaluation of HVOF process parameters","authors":"Lukas Tegelkamp , Maximilian Grimm , Susan Conze , Lutz-Michael Berger , Thomas Lindner , Thomas Lampke","doi":"10.1016/j.surfcoat.2025.132208","DOIUrl":"10.1016/j.surfcoat.2025.132208","url":null,"abstract":"<div><div>Health risks of Co and classification of W and Co as critical raw materials are currently the driving forces behind the search for WC-Co(Cr) replacement. NbC-based hardmetal compositions have just recently emerged and are now under consideration for use as thermally sprayed wear resistant coatings. NbC is proposed to be particularly suitable for combination with Fe-based binders. In this study an agglomerated and sintered 80NbC-15Fe5Cr (wt.-%) powder was processed by means of liquid-fueled HVOF. The experiments were carried out in two series: The influence of spray distance (305 and 395 mm) and nozzle geometry (lengths of 150 and 200 mm with diameters of 11 to 14 mm) were investigated in the first series. Powder feed rate (77 to 114 g/min) and oxygen-fuel-ratio (λ = 1.0 and λ = 1.2) were varied in the second series. In-flight particle velocity of approximately 700 m/s and temperature of 2150 °C resulted in coatings of the highest quality achieved in this study. SEM and optical microscopy of the coatings showed a higher thickness with higher in-flight particle temperatures and porosities between 2.1 and 4.6 %. XRD and EDS analyses revealed the presence of oxygen as FeNb<sub>2</sub>O<sub>6</sub>. Strongly correlated with porosity, Vickers microhardness ranges from approximately 770 to 900 HV0.3. Unidirectional and reciprocating dry sliding wear rates of 1.2 × 10<sup>−6</sup> and 2.1 × 10<sup>−6</sup> mm<sup>3</sup>/(N × m), respectively are fully competitive to those of the reference coating systems WC-CoCr and Cr<sub>3</sub>C<sub>2</sub>-NiCr. Overall, the shorter spray distance with a smaller nozzle was advantageous when combined with λ = 1.0 and powder feed rate of 102 g/min.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"509 ","pages":"Article 132208"},"PeriodicalIF":5.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898746","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}

引用次数: 0

Microstructure and ablation behavior of a novel La2Hf2O7/ZrC-SiC/SiC graded coating for ablative protection up to 2400 °C 新型La2Hf2O7/ZrC-SiC/SiC梯度涂层的显微组织和烧蚀性能

IF 5.3 2区材料科学

Surface & Coatings Technology Pub Date : 2025-04-22 DOI: 10.1016/j.surfcoat.2025.132191

Dawei Wang, Sen Wu, Xin Yang, Xiao Luo, Xiaxiang Zhang, Qizhong Huang

{"title":"Microstructure and ablation behavior of a novel La2Hf2O7/ZrC-SiC/SiC graded coating for ablative protection up to 2400 °C","authors":"Dawei Wang, Sen Wu, Xin Yang, Xiao Luo, Xiaxiang Zhang, Qizhong Huang","doi":"10.1016/j.surfcoat.2025.132191","DOIUrl":"10.1016/j.surfcoat.2025.132191","url":null,"abstract":"<div><div>A novel La<sub>2</sub>Hf<sub>2</sub>O<sub>7</sub>/ZrC-SiC/SiC graded coating with CTE increasing gradually from the inner to outside layers was prepared by pack cementation and supersonic atmospheric plasma spraying. Due to the graded multi-layer structure, the coating exhibits good ablative property after different ablation times. As ablated under 3.2 MW/m<sup>2</sup> oxygen acetylene flame for 30 and 60 s, the ablation rates are increased from −11.3 μm/s, −0.53 mg/s to 6.79 μm/s, 1.12 mg/s. The ablation results demonstrate that La<sub>2</sub>Hf<sub>2</sub>O<sub>7</sub> outer layer maintains good thermal stability without decomposition or phase transformation at 2400 °C, and only partial melting and obvious growth of the La<sub>2</sub>Hf<sub>2</sub>O<sub>7</sub> grains are observed in ablation center. The scoured molten La<sub>2</sub>Hf<sub>2</sub>O<sub>7</sub> phase and the thinning of La<sub>2</sub>Hf<sub>2</sub>O<sub>7</sub> outer layer caused by the further sintering result in the increased ablation rates of the graded coating. The excellent thermal insulation and stability of La<sub>2</sub>Hf<sub>2</sub>O<sub>7</sub> outer layer provides effective protection for internal SiC-ZrC and SiC layers. The integrity three-layer structure and the well protected inner layers demonstrate the effective design of this novel graded coating for thermal protection of C/C composites at 2400 °C.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"508 ","pages":"Article 132191"},"PeriodicalIF":5.3,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864532","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}

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