To see the other types of publications on this topic, follow the link: HEA Coatings.
Journal articles on the topic 'HEA Coatings'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'HEA Coatings.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Gao, Peihu, Ruitao Fu, Jilin Liu, Baiyang Chen, Bo Zhang, Daming Zhao, Zhong Yang, et al. "Influence of Plasma Arc Current on the Friction and Wear Properties of CoCrFeNiMn High Entropy Alloy Coatings Prepared on CGI through Plasma Transfer Arc Cladding." Coatings 12, no. 5 (May 5, 2022): 633. http://dx.doi.org/10.3390/coatings12050633.
Full textAbstract:
High-entropy alloys receive more attention for high strength, good ductility as well as good wear resistance. In this work, CoCrFeNiMn high-entropy alloy (HEA) coatings were deposited on compacted graphite iron through plasma transfer arc at different currents. The microstructure and wear properties of the CoCrFeNiMn HEA coatings were investigated. The coatings are composed of single phase with FCC structure. The CoCrFeNiMn HEA coating had the highest microhardness of 394 ± 21.6 HV0.2 and the lowest wear mass loss when the plasma current was 65 A. All of the HEA coatings had higher friction coefficients than that of the substrate. There were adhesive, abrasive and oxidation wear forms in the HEA coatings with the wear couple of N80 alloy. The HEA coating presented higher friction coefficient and better wear resistance than compacted graphite iron.
2
Ma, Kai, Li Feng, and Zhipeng Wang. "Microstructure and Properties of FeCrMnxAlCu High-Entropy Alloys and Coatings." Coatings 13, no. 8 (August 9, 2023): 1401. http://dx.doi.org/10.3390/coatings13081401.
Full textAbstract:
FeCrMnxAlCu (x = 0.5, 1, 1.5, and 2) high-entropy alloys (HEA) and coatings were prepared through vacuum arc melting and cold spray-assisted induction remelting processes. This study investigated the effect of different Mn contents on the microstructure and wear resistance of HEAs and coatings. The results showed that the high-entropy FeCrMnxAlCu alloy prepared through vacuum arc melting and cold spray-assisted induction remelting processes comprised simple body-centered cubic and face-centered cubic phases with dendritic + interdendrite structures. The coating of the prepared alloys exhibited superior performance compared with the cast alloy. In addition, the hardness of the FeCrMnxAlCu HEA coatings synthesized through induction remelting was 1.4 times higher than that of the cast FeCrMnxAlCu HEA. Moreover, the wear rate of induction-remelted produced HEA coating was reduced by 24% compared with that of vacuum arc-melted produced HEA. The hardness of the induction-remelted produced FeCrMnxAlCu HEA coating initially increased and then decreased with increasing Mn contents. At x = 1, the hardness of FeCrMnAlCu HEA coating reached a maximum value of 586 HV, with a wear rate of 2.95 × 10−5 mm3/(N·m). The main wear mechanisms observed in the FeCrMnxAlCu HEA coatings were adhesive, abrasive, and oxidative.
3
Huang, Jiang, Zhikai Zhu, Hao Wang, Kaiyue Li, Wenqing Shi, and Tianwen Jiao. "Effect of WC Content on Microstructure and Properties of CoCrFeNi HEA Composite Coating on 316L Surface via Laser Cladding." Materials 16, no. 7 (March 28, 2023): 2706. http://dx.doi.org/10.3390/ma16072706.
Full textAbstract:
Laser cladding technology is used to fabricate CoCrFeNi HEA/WC composite coatings with different mass fractions of WC on the surface of 316L stainless steel. The microstructures of HEA/WC composite coatings were analyzed by combining multiple characterization techniques. The results show that the HEA/WC composite coatings have good surface formation without pores and hot cracks, and the metallurgical bonding is well formed between the coating and the 316L SS substrate. Under the action of a laser beam and molten pool, WC particles partially or slightly melt and diffuse to the matrix, which hinders the orderly growth of grains and forms multiple strengthening. The phase structure of the HEA/WC composite coatings is composed of a main phase with FCC. The hardness and corrosion resistance of the HEA/WC composite coatings are clearly enhanced, and the HEA/WC composite coating with 5% WC has optimum properties.
4
Hong, Zhihao, Long Wang, Wei Zhang, Jian Yang, Yongjin Feng, Jijun Yang, Haoxiang Li, Huaqiang Yin, Long Zhang, and Xiaoyu Wang. "Hydrogen Isotope Permeation Behavior of AlCrFeTiNb, AlCrMoNbZr and AlCrFeMoTi High-Entropy Alloys Coatings." Coatings 12, no. 2 (January 28, 2022): 171. http://dx.doi.org/10.3390/coatings12020171.
Full textAbstract:
The hydrogen permeation behavior of novel AlCrFeTiNb, AlCrMoNbZr and AlCrFeMoTi high-entropy alloy (HEA) coatings were investigated. The hydrogen permeability of HEA coatings prepared by magnetron sputtering technology were tested using gas-driven deuterium permeation and electrochemical hydrogen permeation methods. The gas-driven permeation results show that the deuterium permeation resistance of the AlCrFeTiNb coating is the worst because of the unstable structure at a high temperature. Scanning electron microscope (SEM) and X-ray Diffraction (XRD) analysis proved a loose surface morphology of the AlCrFeTiNb coating and demonstrated the formation of iron-based oxides after deuterium permeation experiments. A high content of iron in HEA coating is disadvantageous for improving the hydrogen permeability. Differently, electrochemical hydrogen permeation reveals that the AlCrMoNbZr coating could resist hydrogen permeation better in a corrosive environment (0.2 mol/L KOH solution). The AlCrFeMoTi coating was peeled off after an electrochemical hydrogen permeation test due to the poor corrosion resistance. The hydrogen behavior of HEA coatings was discussed in detail. Our study provides a promising thought on hydrogen permeation of HEA coatings.
5
Luo, Fangyan, Tuchuan Yang, Yang Zhao, Zhengye Xiong, and Jiang Huang. "Effect of W Content on Microstructure and Properties of Laser Cladding CoCrFeNi HEA Coating." Coatings 13, no. 8 (July 25, 2023): 1301. http://dx.doi.org/10.3390/coatings13081301.
Full textAbstract:
The 316L SS surfaces were prepared with CoCrFeNi HEA/W-composite coatings using the laser cladding technique with various mass fractions of W. The mass fractions of W were 10, 20, 30, and 40%. The microstructure of the HEA/W-composite coatings was investigated using a variety of characterization methods. According to the results, the samples were in the BBC phase. In the SEM images, a solid–liquid bonding layer was observed, which indicates the samples had good metallurgical bonding. The W particles prevented the orderly growth of the HEA grains, and a significant refinement of the grains around the W particles occurred. The lattice constants measured by XRD mapping indicate that adding W particles to CoCrFeNi HEA leads to lattice distortion. The hardness of the HEA/W coatings was substantially higher than the substrate and the pure CoCrFeNi coating by hardness measurements and was greatest at a W content of 40%. The hardness of the HEA/W coatings was significantly increased compared to the substrate and the pure CoCrFeNi coating by hardness measurements and was greatest at a W content of 40%. The HEA/W coating was tested for electrochemical corrosion, and a 10% mass fraction of W achieved the highest level of corrosion resistance.
6
Sharma, Ashutosh. "High Entropy Alloy Coatings and Technology." Coatings 11, no. 4 (March 24, 2021): 372. http://dx.doi.org/10.3390/coatings11040372.
Full textAbstract:
Recently, the materials research community has seen a great increase in the development of multicomponent alloys, known as high entropy alloys (HEAs) with extraordinary properties and applications. In surface protection and engineering, diverse applications of HEAs are also being counted to benefit from their attractive performances in various environments. Thermally sprayed HEA coatings have outperformed conventional coating materials and have accelerated further advancement in this field. Therefore, this review article overviews the initial developments and outcomes in the field of HEA coatings. The authors have also categorized these HEA coatings in metallic, ceramic, and composite HEA coatings and discussed various developments in each of the categories in detail. Various fabrication strategies, properties, and important applications of these HEAs are highlighted. Further, various issues and future possibilities in this area for coatings development are recommended.
7
Sun, Jie, Sichao Dai, Dabin Zhang, Wudong Si, Benchi Jiang, Da Shu, Lulu Wu, Chao Zhang, Meisong Zhang, and Xinyan Xiong. "Friction and Wear Properties of CoCrFeNiMnSnx High Entropy Alloy Coatings Prepared via Laser Cladding." Metals 12, no. 7 (July 21, 2022): 1230. http://dx.doi.org/10.3390/met12071230.
Full textAbstract:
Due to its unique single-phase multivariate alloy characteristics and good low-temperature mechanical properties, CoCrFeNiMn high entropy alloy (HEA) has attracted the interest of many researchers in recent years. In this paper, to improve the wear resistance of Q235 alloy steel surface, CoCrFeNiMnSnx HEA coatings were prepared on the surface of Q235 steel via laser cladding. X-ray diffractometry, optical microscopy, scanning electron microscopy (SEM), and energy dispersive spectrometry were used to determine the microstructure and chemical composition. The research findings revealed that the CoCrFeNiMn HEA coatings were formed from a single FCC phase. As the Sn content in the coating increased, a new MnNi2Sn phase formed. Microhardness and friction and wear results showed that when the mole content of Sn was 0.2, the hardness of the CoCrFeNiMn HEA coating was increased by approximately 45%, the friction coefficient decreased by 0.168, and the wear loss decreased by 16.6%. Three-dimensional noncontact morphology and SEM results revealed that the wear mechanisms of CoCrFeNiMn HEA coatings were abrasive wear, delamination wear and a small amount of oxidative wear under dry friction conditions, whereas the friction mechanisms of CoCrFeNiMnSn0.2 HEA coatings were primarily abrasive wear and oxidative wear.
8
Niu, Xuelian, Zhongqi Luan, Yan Mei, and You Yu. "The corrosion resistance of Al-Fe-Co-Cr-Ni-Cu high entropy alloy coatings." Journal of Physics: Conference Series 2535, no. 1 (June 1, 2023): 012023. http://dx.doi.org/10.1088/1742-6596/2535/1/012023.
Full textAbstract:
Abstract A high entropy alloy AlxFeCoCrNiCu (x=0.5, 1) coating was prepared by the electron beam evaporation method on the surface of the steel. The influence of aluminum content on the corrosion resistance of the coating is discussed. The obtained results show that the HEA coatings retain the HEA phase structure without any phase change. The polarization curves show that the high entropy alloy coating of Al0.5FeCoCrNiCu had better corrosion resistance in 0.5 mol/L H2SO4 solution and 1 mol/L NaCl solution. This design of the HEA coatings provides a novel method for steel corrosion-resistant materials.
9
Liu, Pengfei, Wudong Si, Dabin Zhang, Sichao Dai, Benchi Jiang, Da Shu, Lulu Wu, Chao Zhang, and Meisong Zhang. "Microstructure and Friction Properties of CoCrFeMnNiTix High-Entropy Alloy Coating by Laser Cladding." Materials 15, no. 13 (July 3, 2022): 4669. http://dx.doi.org/10.3390/ma15134669.
Full textAbstract:
To enhance the friction and wear properties of 40Cr steel’s surface, CoCrFeMnNi high-entropy alloy (HEA) coatings with various Ti contents were prepared using laser cladding. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were used to characterize the phase composition, microstructure, and chemical composition of the samples. The findings demonstrated that the CoCrFeMnNiTix HEA coatings formed a single FCC phase. Fe2Ti, Ni3Ti, and Co2Ti intermetallic compounds were discovered in the coatings when the molar ratio of Ti content was greater than 0.5. The EDS findings indicated that Cr and Co/Ni/Ti were primarily enriched in the dendrite and interdendrite, respectively. Ti addition can effectively enhance the coating’s mechanical properties. The hardness test findings showed that when the molar ratio of Ti was 0.75, the coating’s microhardness was 511 HV0.5, which was 1.9 times the hardness of the 40Cr (256 HV0.5) substrate and 1.46 times the hardness of the CrCrFeMnNi HEA coating (348 HV0.5). The friction and wear findings demonstrated that the addition of Ti can substantially reduce the coating’s friction coefficient and wear rate. The coating’s wear resistance was the best when the molar ratio of Ti was 0.75, the friction coefficient was 0.296, and the wear amount was 0.001 g. SEM and 3D morphology test results demonstrated that the coating’s wear mechanism changed from adhesive wear and abrasive wear to fatigue wear and abrasive wear with the increase in Ti content.
10
Wang, Leilei, Zhuanni Gao, Mengyao Wu, Fei Weng, Ting Liu, and Xiaohong Zhan. "Influence of Specific Energy on Microstructure and Properties of Laser Cladded FeCoCrNi High Entropy Alloy." Metals 10, no. 11 (November 2, 2020): 1464. http://dx.doi.org/10.3390/met10111464.
Full textAbstract:
Specific energy is a key process parameter during laser cladding of high entropy alloy (HEA); however, the effect of specific energy on the microstructure, hardness, and wear resistance of HEA coating has not been completely understood in the literature. This paper aims at revealing the influence of specific energy on the microstructure and properties of laser cladded FeCoCrNi high entropy alloy on the Ti6Al4V substrate, and further obtains feasible process parameters for preparation of HEA coating. Results indicate that there are significant differences in the microstructure and properties of the coatings under different specific energy. The increase of specific energy plays a positive role in coarsening the microstructure, promoting the diffusion of Ti from the substrate to HEA coating, and subsequently affects the hardness of samples. The HEA coating is mainly composed of the face-centered cubic phase and body-centered cubic phase, precipitating a small amount of Fe-Cr phase and Laves phase. Metallurgical bonding is obtained between the base metal and the coatings of which the bonding region is mainly composed of columnar crystal and shrinkage cavities. The microhardness of the HEA coating reaches 1098 HV, which is about 200% higher than that of the TC4 substrate, and the wear resistance is significantly improved by the HEA coating.
11
Liu, Yang, Zhixiang Xu, Gaojie Xu, and Hongyong Chen. "Influence of Al Addition on the Microstructure and Wear Behavior of Laser Cladding FeCoCrNiAlx High-Entropy Alloy Coatings." Coatings 13, no. 2 (February 13, 2023): 426. http://dx.doi.org/10.3390/coatings13020426.
Full textAbstract:
In order to improve the wear properties of FeCoCrNi high entropy alloy (HEA), laser cladding was applied to fabricate FeCoCrNiAlx HEA coatings with different Al additions. The Al-modified coatings exhibited excellent metallurgical bonding interfaces with the substrates. The microstructure of FeCoCrNiAl0.5 coating was the same as of the FeCoCrNi coating: face-centered cubic (FCC). However, the microstructure of FeCoCrNiAl was different: body-centered cubic (BCC) with more Al atoms distributed inside the grains. As the Al content in the coating was increased, the hardness increased as well from 202 to 546 HV0.2, while CoF and wear rate decreased from 0.62 to 0.1 and from 8.55 × 10−7 to 8.24 × 10−9 mm3/(Nm), respectively. The wear mechanisms changed from the mixture of abrasive, adhesive, and oxidative wear patterns to the mixture of abrasive and oxidative patterns. Such a change indicates that the Al addition indeed improved the wear resistance of FeCoCrNiAlx HEA coatings. Our results expand knowledge on HEA coating applications as wear-resistant materials in various applied industrial fields.
12
Wang, Zhao, Nan Lan, Yong Zhang, and Wanrong Deng. "Microstructure and Properties of MAO-Cu/Cu-(HEA)N Composite Coatings on Titanium Alloy." Coatings 12, no. 12 (December 3, 2022): 1877. http://dx.doi.org/10.3390/coatings12121877.
Full textAbstract:
In this paper, MAO-Cu/Cu-(HEA)N composite coatings on TC4 titanium alloy were prepared by combining micro arc oxidation (MAO) with magnetron sputtering (MS) to enhance the wear resistance and antibacterial ability of the substrate in simulated seawater. The number of micropores on the surface of the composite coatings decreased with increasing CuSO4 concentration in the electrolyte, causing the surfaces to be flat and smooth. XPS and EDS analyses revealed that the MAO-Cu/Cu-(HEA)N composite coatings predominately contained TiO2, Cu2O, and (HEA)N. Moreover, the addition of CuSO4 increased the growth rate of the MAO coatings. Comparatively, the MAO-Cu/Cu-(HEA)N composite coating with 5 g/L CuSO4 showed superior wear resistance, reduced friction coefficient (approximately 0.2), and shallow and narrow grinding cracks were observed compared to the other coatings. Antibacterial experiments showed that the MAO-Cu/Cu-(HEA)N composite coatings had better bacterial killing effects than the TC4 substrate, which is of great significance to the antifouling abilities of titanium alloys in marine applications.
13
Lin, Cheng, and Yonggang Yao. "Corrosion-Resistant Coating Based on High-Entropy Alloys." Metals 13, no. 2 (January 20, 2023): 205. http://dx.doi.org/10.3390/met13020205.
Full textAbstract:
Metal corrosion leads to serious resource waste and economic losses, and in severe cases, it can result in catastrophic safety incidents. As a result, proper coatings are often employed to separate metal alloys from the ambient environment and thus prevent or at least slow down corrosion. Among various materials, high-entropy alloy coatings (HEA coating) have recently received a lot of attention due to their unique entropy-stabilized structure, superior physical and chemical properties, and often excellent corrosion resistance. To address the recent developments and remaining issues in HEA coatings, this paper reviews the primary fabrication methods and various elemental compositions in HEA coatings and highlights their effects on corrosion resistance properties. It is found that FeCoCrNi-based and refractory high-entropy alloy coatings prepared by the laser/plasma cladding method typically show better corrosion resistance. It also briefly discusses the future directions toward high-performing corrosion-resistant coatings based on HEA design.
14
Liang, Hui, Bing Yang Gao, Ya Ning Li, Qiu Xin Nie, and Zhi Qiang Cao. "Microstructures and Wear Resistance of Al1.5CrFeNiTi0.5 and Al1.5CrFeNiTi0.5W0.5 High Entropy Alloy Coatings Manufactured by Laser Cladding." Materials Science Forum 956 (June 2019): 154–59. http://dx.doi.org/10.4028/www.scientific.net/msf.956.154.
Full textAbstract:
For the purpose of expanding the application scope of HEA coating manufactured on the surface modification of materials, in this work, the Al1.5CrFeNiTi0.5 and Al1.5CrFeNiTi0.5W0.5 HEA coatings were successfully manufactured using laser cladding method on SUS304. The microstructures and wear resistance of coatings are researched systematically. It is found that the W0 and W0.5 HEA coatings all exhibit the dendritic structure, which are constituted by BCC phases and Laves phases. With W element addition, the phase structures of W0.5 coating remain unchanged. W is dissolved in both two phases, but the solid solubility in Laves phase is higher compared to that in BCC phase. W0.5 coating with the highest microhardness of 848.34 HV, and the W0 coating with the microhardness of 811.45 HV, both of whose microhardness are four times more than that of SUS304 substrate. Among all samples, the W0.5 coating shows the optimal wear performance because of its larger content of hard second phase ( Laves phase).
15
Liu, Dezheng, Jing Zhao, Yan Li, Wenli Zhu, and Liangxu Lin. "Effects of Boron Content on Microstructure and Wear Properties of FeCoCrNiBx High-Entropy Alloy Coating by Laser Cladding." Applied Sciences 10, no. 1 (December 19, 2019): 49. http://dx.doi.org/10.3390/app10010049.
Full textAbstract:
The FeCoCrNiBx high-entropy alloy (HEA) coatings with three different boron (B) contents were synthesized on Q245R steel (American grade: SA515 Gr60) by laser cladding deposition technology. Effects of B content on the microstructure and wear properties of FeCoCrNiBx HEA coating were investigated. In this study, the phase composition, microstructure, micro-hardness, and wear resistance (rolling friction) were investigated by X-ray diffraction (XRD), a scanning electron microscope (SEM), a micro hardness tester, and a roller friction wear tester, respectively. The FeCoCrNiBx coatings exhibited a typical dendritic and interdendritic structure, and the microstructure was refined with the increase of B content. Additionally, the coatings were found to be a simple face-centered cubic (FCC) solid solution with borides. In terms of mechanical properties, the hardness and wear resistance ability of the coating can be enhanced with the increase of the B content, and the maximum hardness value of three HEA coatings reached around 1025 HV0.2, which is higher than the hardness of the substrate material. It is suggested that the present fabricated HEA coatings possess potentials in application of wear resistance structures for Q245R steel.
16
Padamata, Sai Krishna, Andrey Yasinskiy, Valentin Yanov, and Gudrun Saevarsdottir. "Magnetron Sputtering High-Entropy Alloy Coatings: A Mini-Review." Metals 12, no. 2 (February 11, 2022): 319. http://dx.doi.org/10.3390/met12020319.
Full textAbstract:
Surface coatings can enhance the substrate material’s properties and increase its lifetime. HEA-based materials have been extensively investigated as coating materials due to their superior hardness, excellent oxidation and corrosion resistance, effective diffusion barrier properties and wear resistance. Magnetron sputtering has been regarded as one of the most efficient methods for the deposition of HEA-based thin films. Metallic- and nitride-based HEA coatings can be easily deposited by introducing N2 gas along with the Ar in the reaction chamber. The parameters such as target composition, bias voltage, sputtering power and notably, gas flow ratio, influence the thin film’s morphology and mechanical properties.
17
Lu, Kefeng, Jian Zhu, Delin Guo, Minghui Yang, Huajian Sun, Zekun Wang, Xidong Hui, and Yongling Wu. "Microstructures, Corrosion Resistance and Wear Resistance of High-Entropy Alloys Coatings with Various Compositions Prepared by Laser Cladding: A Review." Coatings 12, no. 7 (July 19, 2022): 1023. http://dx.doi.org/10.3390/coatings12071023.
Full textAbstract:
Nowadays, high-entropy alloys (HEAs) have become a hot research topic in the field of coating materials. However, HEAs have a large wide range of compositional systems, and the differences in their composition inevitably lead to the significant variations in the matching process parameters of laser cladding and post-treatment methods, which in turn give the coatings a broad range of microstructures and protective properties. Therefore, it is crucial to review and summarize the research progresses on laser cladding HEA coatings to provide a reference for obtaining high-performance HEA coatings and further expand the application of HEA coatings. This work describes the working mechanism of laser cladding and illustrates the advantages and drawbacks of laser cladding in detail. The effects of the addition of alloying elements, process parameters and post-treatment techniques on the microstructures and properties of the coatings are thoroughly reviewed and analyzed. In addition, the correlations between the chemical compositions of HEAs, process parameters of laser cladding, post-treatment techniques and the microstructure and protective properties of the coatings are investigated and summarized. On this basis, the future development direction of HEA coatings is outlined.
18
Lindner, Thomas, Hendrik Liborius, Gerd Töberling, Sabrina Vogt, Bianca Preuß, Lisa-Marie Rymer, Andreas Schubert, and Thomas Lampke. "High-Speed Laser Metal Deposition of CrFeCoNi and AlCrFeCoNi HEA Coatings with Narrow Intermixing Zone and Their Machining by Turning and Diamond Smoothing." Coatings 12, no. 7 (June 21, 2022): 879. http://dx.doi.org/10.3390/coatings12070879.
Full textAbstract:
The processing of high-entropy alloys (HEAs) via laser metal deposition (LMD) is well known. However, it is still difficult to avoid chemical intermixing of the elements between the coating and the substrate. Therefore, the produced coatings do not have the same chemical composition as the HEA feedstock material. Single-layer CrFeCoNi and AlCrFeCoNi HEA coatings were deposited using high-speed laser metal deposition (HS-LMD). Elemental mapping confirmed a good agreement with the chemical composition of the powder feedstock material, and revealed that chemical intermixing was confined to the immediate substrate interface. The coatings are characterized by a homogeneous structure with good substrate bonding. The machining of these coatings via turning is possible. Subsequent diamond smoothing results in a strong decrease in the surface roughness. This study presents a complete manufacturing chain for the production of high-quality HS-LMD HEA coatings.
19
Xu, Yiku, Zhiyuan Li, Jianru Liu, Yongnan Chen, Fengying Zhang, Lei Wu, Jianmin Hao, and Lin Liu. "Microstructure Evolution and Properties of Laser Cladding CoCrFeNiTiAlx High-Entropy Alloy Coatings." Coatings 10, no. 4 (April 9, 2020): 373. http://dx.doi.org/10.3390/coatings10040373.
Full textAbstract:
High-entropy alloy (HEA) coatings of CoCrFeNiTiAlx (x = 0, 0.5, 1, 1.5, 2) were prepared on the surface of AISI1045 steel by laser cladding. The effects of the Al content on the microstructure, composition, phase constitution, and wear and corrosion resistance of the coatings were investigated. The results showed that when increasing the Al element content from 0 to 0.5, the phase constitution of the CoCrFeNiTiAlx coating changed from a single Face-centered cubic (FCC) phase to Body-centered cubic 1 (BCC1) and Body-centered cubic 2 (BCC2) phases, with a small amount of Laves phase, which obviously improved the friction and corrosion resistance of the coating. With further enhancing of the Al content, the amount of BCC1 phase increased, while the BCC2 phase and the Laves phase decreased. The CoCrFeNiTiAl2 HEA coating transformed into a single BCC1 phase, with retrogressive wear and corrosion resistance. It was found that the Al0.5 alloy coating exhibits excellent wear resistance, high hardness, and corrosion resistance in a 3.5 wt.% NaCl solution. Furthermore, the effect of the Al content on the microstructure, phase, and the relating properties of the CoCrFeNiTiAlx HEA coatings is also discussed.
20
Lu, Kefeng, Jian Zhu, Wenqing Ge, and Xidong Hui. "Progress on New Preparation Methods, Microstructures, and Protective Properties of High-Entropy Alloy Coatings." Coatings 12, no. 10 (October 5, 2022): 1472. http://dx.doi.org/10.3390/coatings12101472.
Full textAbstract:
Currently, the preparations of high-entropy alloy (HEA) coatings have developed into new methods such as thermal spraying, electrospark deposition technology, and magnetron sputtering. The microstructures and protective properties of HEA coatings prepared by different methods are bound to be different. Moreover, because HEAs have a wide range of composition systems, the difference in composition will inevitably lead to a change in process parameters and post-treatment methods, and then affect the microstructures and protective properties. This paper introduces the working mechanism of thermal spraying, electrospark deposition technology, and magnetron sputtering, compares the advantages and disadvantages of each method, and focuses on the influences of the compositions, process parameters, and post-treatment process on the microstructures and properties of the coating. Furthermore, this paper outlines the correlation between preparation methods, process parameters, microstructures, and properties, which will provide a reference for further development of the application of high-entropy alloy coatings. On this basis, the future development direction of HEA coatings is prospected.
21
Kang, Jiajie, Yi Niu, Yongkuan Zhou, Yunxiao Fan, and Guozheng Ma. "Wear Resistance Prediction of AlCoCrFeNi-X (Ti, Cu) High-Entropy Alloy Coatings Based on Machine Learning." Metals 13, no. 5 (May 11, 2023): 939. http://dx.doi.org/10.3390/met13050939.
Full textAbstract:
In order to save the time and cost of friction and wear experiments, the coating composition (different contents of Al, Ti, and Cu elements), ratio of hardness and elastic modulus (H3/E2), vacuum heat treatment (VHT) temperature, and wear form were used as input variables, and the wear rates of high-entropy alloy (HEA) coatings were used as output variables. The dataset was entirely obtained by experiment. Four machine learning algorithms (classification and regression tree (CART), random forest (RF), gradient boosting decision tree (GBDT), and adaptive boosting (AdaBoost)) were used to predict the wear resistance of HEA coatings based on a small amount of data. The results show that except for the GBDT model, the other three models had good performance. Because of the small amount of data, the CART model demonstrated the best prediction performance and can provide guidance for predicting the wear resistance of AlCoCrFeNi-X (Ti, Cu) HEA coatings for drilling equipment. Furthermore, the contribution of different factors to the wear rate of AlCoCrFeNi-X (Ti, Cu) HEA coatings was obtained. Al content had the greatest influence on wear rate, followed by H3/E2, wear form, and VHT temperature.
22
Wang, Wenrui, Wu Qi, Lu Xie, Xiao Yang, Jiangtao Li, and Yong Zhang. "Microstructure and Corrosion Behavior of (CoCrFeNi)95Nb5 High-Entropy Alloy Coating Fabricated by Plasma Spraying." Materials 12, no. 5 (February 27, 2019): 694. http://dx.doi.org/10.3390/ma12050694.
Full textAbstract:
In this paper, the (CoCrFeNi)95Nb5 high-entropy alloy (HEA) coating with a thickness of 500 μm on Q235 steel substrate was fabricated by plasma spraying. The microscopic results showed that a new Laves phase is formed in the (CoCrFeNi)95Nb5 HEA coating compared to the HEA powder, and elemental segregation occurs between the dendrites and the interdendrites of the coating, while the interdendritic phase enriches with the Cr and Nb. The phase composition change and elemental segregation behavior were mainly due to the faster cooling rate of the plasma spraying technique. At the junction of the coating and the substrate, the HEA coating bonded well to the substrate; in addition, the width of transition zone was merely 2 μm. The microhardness of the (CoCrFeNi)95Nb5 HEA coating was 321 HV0.5, which is significantly higher than that of the substrate. In terms of corrosion resistance, the (CoCrFeNi)95Nb5 HEA coating has good corrosion resistance in NaCl solution. Although the corrosion form was pitting corrosion, the pitting potential of the (CoCrFeNi)95Nb5 HEA coating was significantly higher than that of other coatings, which was mainly because of the dense passivation film formed by Cr and Nb on the surface of the coating. Once the passivation film was destroyed by Cl−, the selective corrosion occurred on the surface of the (CoCrFeNi)95Nb5 HEA coating. In summary, the (CoCrFeNi)95Nb5 HEA coating prepared by plasma spraying technology can significantly improve the corrosion resistance and mechanical properties of the Q235 steel substrate.
23
Jiang, Hui, Kaiming Han, Dayan Li, and Zhiqiang Cao. "Synthesis and Characterization of AlCoCrFeNiNbx High-Entropy Alloy Coatings by Laser Cladding." Crystals 9, no. 1 (January 20, 2019): 56. http://dx.doi.org/10.3390/cryst9010056.
Full textAbstract:
AlCoCrFeNiNbx (x in molar ratio x = 0, 0.25, 0.5, 0.75, and 1.0) high-entropy alloy (HEA) coatings were manufactured on 304 stainless steel by laser cladding. The constituent phases, microstructures, chemical composition, micro-hardness and wear resistance of the HEA coatings were investigated respectively by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), a Vickers hardness tester and a friction/wear testing machine. It was found that an AlCoCrFeNi alloy coating without Nb consisted of body-centered-cubic (BCC) and order BCC (B2) phases, while the AlCoCrFeNiNbx (x > 0) alloy coatings consisted of BCC, B2 and Laves phases. Microstructures of the AlCoCrFeNiNbx alloy coatings evolved from equiaxed grain (x = 0) to hypoeutectic (0.25 ≤ x < 0.75), then to full eutectic (x = 0.75), and finally to hypereutectic (x > 0.75). With increasing Nb content, the Vickers hardness values increased. AlCoCrFeNiNb0.75 alloy coating with a fully eutectic microstructure demonstrated the best wear resistance among the AlCoCrFeNiNbx (x ≥ 0) alloy coatings.
24
Xu, Li, Huiling Du, Jia Liu, Danni Feng, and Siyu Xia. "Microstructure, Mechanical, and Electrochemical Properties of SiC Particle Reinforced CoCrFeNiCu High-Entropy Alloy Coatings." Coatings 12, no. 4 (April 11, 2022): 519. http://dx.doi.org/10.3390/coatings12040519.
Full textAbstract:
SiC particle reinforced CoCrFeNiCu high-entropy alloy (HEA) coatings (CoCrFeNiCu(SiC)x, x = 0, 5, 10, 15 wt%) were successfully fabricated on 316L stainless steel via laser cladding technique. The effects of SiC particles on the microstructure, mechanical, and electrochemical properties of CoCrFeNiCu HEA were investigated. The results showed that the as-fabricated CoCrFeNiCu(SiC)x HEA coatings is a FCC structure, and a secondary phase formed of Cr7C3 at the grain boundaries. Grain boundary strengthening enhances the mechanical properties of CoCrFeNiCu(SiC)x HEA coatings. Especially for CoCrFeNiCu(SiC)15 HEA coatings, the microhardness, wear weight, and friction coefficient were 568.4 HV, 0.9 mg, and 0.35, respectively. With the increasing of SiC content, the corrosion resistance of CoCrFeNiCu(SiC)x HEA coatings was enhanced in 3.5% NaCl solution. The CoCrFeNiCu(SiC)10 coatings showed better performance than others when they were evaluated for corrosion. These results indicated that the CoCrFeNiCu(SiC)x HEA coatings could significantly enhance the wear, friction, and corrosion resistance properties of the 316L stainless steel.
25
Ghadami, Farzin, Mohammad Amin Davoudabadi, and Soheil Ghadami. "Cyclic Oxidation Properties of the Nanocrystalline AlCrFeCoNi High-Entropy Alloy Coatings Applied by the Atmospheric Plasma Spraying Technique." Coatings 12, no. 3 (March 10, 2022): 372. http://dx.doi.org/10.3390/coatings12030372.
Full textAbstract:
Microcrystalline and nanocrystalline AlCrFeCoNi high-entropy alloy (HEA) coatings were applied on Inconel 718 superalloy using the atmospheric plasma spraying (APS) process. The high-temperature oxidation behavior of the microcrystalline and nanocrystalline AlCrFeCoNi HEA-coated superalloy was examined at 1100 °C under the air atmosphere for 50 cycles under cyclic heating and cooling (1 h for each cycle). The oxidation kinetics of both nanocrystalline- and microcrystalline-coated superalloys were accordingly analyzed by weight change measurements. We noted that the uncoated and coated samples followed the parabolic rate law of the oxidation. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDS), elemental mapping and X-ray photoelectron spectroscopy (XPS) were used to analyze the oxidized coated and uncoated samples. In the HEA-coated superalloy, Fe, Ni, Co and Al were oxidized in the inter-splat region, whereas the splats, which consisted mainly of Ni and Cr, remained unoxidized. Due to the formation of compact and adhesive thin NiO, CoO oxides and spinels together with the Al2O3 oxide scale on the surface of the coating during oxidation, the developed nanocrystalline HEA coating showed better oxidation resistance compared with the microcrystalline HEA coating.
26
Batraev, Igor S., Vladimir Yu Ulianitsky, Alexandr A. Shtertser, Dina V. Dudina, Konstantin V. Ivanyuk, Vyacheslav I. Kvashnin, Yaroslav L. Lukyanov, Marina N. Samodurova, and Evgeny A. Trofimov. "Fabrication of High-Entropy Alloys Using a Combination of Detonation Spraying and Spark Plasma Sintering: A Case Study Using the Al-Fe-Co-Ni-Cu System." Metals 13, no. 9 (August 26, 2023): 1519. http://dx.doi.org/10.3390/met13091519.
Full textAbstract:
The use of pre-alloyed powders as high-entropy alloy (HEA) coating precursors ensures a predetermined (unaltered) elemental composition of the coating with regard to the feedstock powder. At the same time, it is interesting to tackle a more challenging task: to form alloy coatings from powder blends (not previously alloyed). The powder-blend-based route of coating formation eliminates the need to use atomization or ball milling equipment for powder preparation and allows for the introduction of additives into the material in a flexible manner. In this work, for the first time, a HEA was obtained using detonation spraying (DS) followed by spark plasma sintering (SPS). A powder mixture with a nominal composition of 10Al-22.5Fe-22.5Co-22.5Ni-22.5Cu (at.%) was detonation-sprayed to form a multicomponent metallic coating on a steel substrate. The elemental composition of the deposited layer was (9 ± 1)Al-(10 ± 1)Fe-(20 ± 1)Co-(34 ± 1)Ni-(27 ± 1)Cu (at.%), which is different from that of the feedstock powder because of the differences in the deposition efficiencies of the metals during DS. Despite the compositional deviations, the deposited layer was still suitable as a precursor for a HEA with a configurational entropy of ~1.5R, where R is the universal gas constant. The subsequent SPS treatment of the substrate/coating assembly was carried out at 800–1000 °C at a uniaxial pressure of 40 MPa. The SPS treatment of the deposited layer at 1000 °C for 20 min was sufficient to produce an alloy with a single-phase face-centered cubic structure and a porosity of <1%. Interestingly, the hardness values of the as-sprayed and SPS-treated coatings were close to each other (~320 HV0.3). The hardness of the coatings measured in two perpendicular directions did not differ significantly. The features of the DS–SPS route of the formation of HEA coatings and its potential applications are discussed.
27
Wang, Wenrui, Qi Sun, Dingzhi Wang, Junsong Hou, Wu Qi, Dongyue Li, and Lu Xie. "Microstructure and Mechanical Properties of the ((CoCrFeNi)95Nb5)100−xMox High-Entropy Alloy Coating Fabricated under Different Laser Power." Metals 11, no. 9 (September 17, 2021): 1477. http://dx.doi.org/10.3390/met11091477.
Full textAbstract:
In this paper, the ((CoCrFeNi)95Nb5)100−xMox (x = 1, 1.5 and 2) high-entropy alloy (HEA) coatings were fabricated on the substrate of 45# steel by laser cladding process under different laser beam power. The influence of laser beam power and molybdenum element content on the microstructure and microhardness of the HEA coatings was investigated. Results show that the HEA coatings were composed of face-centered cubic (FCC) phase and Laves phase, had low porosity, and bonded well to the substrate. The Mo1 coating is composed of cellular dendritic structures and columnar dendritic structures. With the increase of molybdenum element content, the columnar dendritic structures disappeared, the grains are refined, and the arrangement of grains is more compact. The volume fraction of the interdendritic phase under the laser beam power of 800 W was small and irregular. After the laser beam power was increased to 1000 W, the volume fraction of the interdendritic phase was increased. Under the laser beam power of 1200 W, the volume fraction of the interdendritic phase was small again. Therefore, the coatings fabricated under the laser beam power of 1000 W had a larger volume fraction of the interdendritic phase and higher microhardness. With the increase in molybdenum content, the grain changed from columnar dendrite to cellular dendrite, and the microhardness of the coating increased. The characteristics of the laser cladding process, the formation of Laves phase, and the fine grain strengthening lead to high microhardness of the coatings.
28
Gromov, V. E., S. V. Konovalov, O. A. Peregudov, M. O. Efimov, and Yu A. Shlyarova. "Coatings from high-entropy alloys: State and prospects." Izvestiya. Ferrous Metallurgy 65, no. 10 (October 30, 2022): 683–92. http://dx.doi.org/10.17073/0368-0797-2022-10-683-692.
Full textAbstract:
The authors made a brief review of recent publications by foreign and domestic researchers on the structure, phase composition, and properties of films and coatings of five-component high-entropy alloys (HEA) on various substrates and modification of the HEA surface by various types of processing. The main methods of applying films and coatings are considered: magnetron sputtering, thermal sputtering, laser sputtering, and electrodeposition. Particular attention is paid to the deposition of coatings on stainless steels and titanium alloys. The positive change in the tribological, strength properties, and corrosion resistance of film coatings in a wide temperature range is analyzed and possible causes of the observed effects are discussed. The role of solid solution strengthening, formation of fine-grained structure, and the formation of oxide layers enriched with one of the HEA components were taken into account. The authors identified new methods for applying coatings from HEA and subsequent processing. Using Nb and Ti doping as an example, their role in increasing microhardness, wear resistance, and reducing the friction coefficient in coatings were revealed. Electrolytic polishing, electroerosive machining, mechanical polishing and their combination are considered among the methods of HEA surface treatment. A number of works propose a method of powder borating to increase the surface strength and wear resistance of HEAs. The paper considers analysis of works on electron-beam processing as one of the promising and high efficient methods of HEA surface hardening.
29
Cui, Wenyuan, Wei Li, Wei-Ting Chen, and Frank Liou. "Laser Metal Deposition of an AlCoCrFeNiTi0.5 High-Entropy Alloy Coating on a Ti6Al4V Substrate: Microstructure and Oxidation Behavior." Crystals 10, no. 8 (July 23, 2020): 638. http://dx.doi.org/10.3390/cryst10080638.
Full textAbstract:
Ti6Al4V has been recognized as an attractive material, due to its combination of low density and favorable mechanical properties. However, its insufficient oxidation resistance has limited the high-temperature application. In this work, an AlCoCrFeNiTi0.5 high-entropy alloy (HEA) coating was fabricated on a Ti6Al4V substrate using laser metal deposition (LMD). The microstructure and isothermal oxidation behaviors were investigated. The microstructure of as-deposited HEA exhibited a Fe, Cr-rich A2 phase and an Al, Ni, Ti-enriched B2 phase. Its hardness was approximately 2.1 times higher than that of the substrate. The oxidation testing at 700 °C and 800 °C suggested that the HEA coating has better oxidation resistance than the Ti6Al4V substrate. The oxide scales of the Ti6Al4V substrate were mainly composed of TiO2, while continuous Al2O3 and Cr2O3 were formed in the HEA coatings and could be attributed to oxidation resistance improvement. This work provides an approach to mitigate the oxidation resistance of Ti6Al4V and explore the applicability of the HEA in a high-temperature environment.
30
Zhang, Kaige, Danqing Yin, Bin Wang, Maochang Li, Xiao Xiao, Ning Ma, and Keke Zhang. "Ultrasonic Cavitation Erosion Behavior of CoCrxFeMnNi High-Entropy Alloy Coatings Prepared by Plasma Cladding." Metals 13, no. 3 (March 3, 2023): 515. http://dx.doi.org/10.3390/met13030515.
Full textAbstract:
CoCrxFeMnNi (x represents the atomic percentage of Cr element, x = 20, 25, 30, and 35, denoted as Cr20, Cr25, Cr30, and Cr35 alloys) high-entropy alloy (HEA) coatings were cladded by plasma arc on the surface of 0Cr13Ni5Mo steel. The effects of Cr elements on the cavitation erosion mechanisms were studied by comparing the differences of microstructure, microhardness, cavitation erosion volume loss (CVL), cavitation erosion volume loss rate (CER), and eroded surface morphologies between the coatings. As the Cr content increased, the microhardness of the coatings increased continuously, and the microstructure transformed into fine dendrites. The microhardnesses of Cr20, Cr25, Cr30, and Cr35 were 223.9 HV, 250.5 HV, 265.2 HV, and 333.7 HV, respectively. With structural change, the slip pattern shifted from uniform distribution to distribution along the grain boundary, increasing slip resistance. Additionally, strain hardening capacity increased with reduced stacking fault energy (SFE). The resistance to cavitation erosion (CR) of the HEA increased with the increase in Cr content. The CVL of 20 h cavitation erosion of Cr35 coating was only 26.84% of that of 0Cr13Ni5Mo steel, and the peak CER was only 28.75% of that of 0Cr13Ni5Mo steel. The fracture damage mechanisms of the four HEA coatings were an obvious lamellar structure and fibrous fracture.
31
Bo, Shenghong, Yaxiong Guo, and Qibin Liu. "[(AlxTi1−x)-(FeCoNi)12](AlxTi1−x)0.5Cr2.5 High-Entropy Alloy Coating by Laser Cladding." Metals 12, no. 5 (April 27, 2022): 740. http://dx.doi.org/10.3390/met12050740.
Full textAbstract:
To prolong the service life of the stirrer impeller made by SUS 904L austenitic super-stainless steel, a series of [(AlxTi1−x)-(FeCoNi)12](AlxTi1−x)0.5Cr2.5 high-entropy alloy (HEA) compositions were designed based on the cluster-plus-glue-atom model. The HEAs’ coatings were successfully fabricated by laser cladding technology. The microstructure, microhardness, wear resistance and corrosion resistance were measured by a scanning electron microscope, transmission electron microscope, microhardness tester, wear machine and electrochemical workstation, respectively. The experimental results indicate that the phase structures of the [(AlxTi1−x)-(FeCoNi)12](AlxTi1−x)0.5Cr2.5 (x = 0, 0.5, 1) HEA coatings mainly consist of a single face-centered-cubic solid solution and the coatings produce BCC phase with the increase of Ti content. When x = 0, the coating has the highest hardness (402.3 HV0.2) which is 1.92 times that of 904L austenitic super-stainless steel (209.0 HV0.2), the lowest wear volume (0.866 mm3) and the best corrosion resistance. The addition of Ti refined the microstructure of the coatings and promoted the formation of BCC phase, which improved the hardness and wear resistance of the coatings. Considering the wide sources of Ti, Fe and Co elements and the convenience of laser cladding, the coating can provide a cheap protective layer for 904L stainless steel.
32
Liu, Shi Da, Cun Yuan Peng, Ming Xing Ma, Wen Jin Liu, and Wei Ming Zhang. "Effect of Mn Contents on the Phase Transition of the High Entropy Alloy Prepared by Laser Cladding." Materials Science Forum 849 (March 2016): 64–70. http://dx.doi.org/10.4028/www.scientific.net/msf.849.64.
Full textAbstract:
Al1.3FeCoNiCuCr high entropy alloy (HEA) coatings were prepared by pre-placed laser cladding on 921A steel substrate, and the study on the phase transition of the Al1.3FeCoNiCuCr coating due to the introduction of Mn was conducted. The combination of TEM and XRD results showed that the Al1.3FeCoNiCuCr HEA coatings without Mn addition typically consisted of two kinds of grains, i.e., one is composed of only FCC phase, and the another is a mixture of BCC and FCC phases. The two phases were of similar ratio in the coatings, while nanoparticulate precipitates were observed in the bcc phase. When 3 wt. % Mn was introduced into the alloy, the coatings consisted of also FCC and BCC phase. However, most of the grains were in FCC phase, while the BCC phase with a lath shape only distributed between the FCC phases. High hardness nanobanded precipitates were observed in the FCC phase. It is clearly revealed that the phase structure of Al1.3FeCoNiCuCr coatings undergoes a dramatic transition due to the introducing of Mn.
33
Ren, Xiangyu, Wenlei Sun, Zefeng Sheng, Minying Liu, Hujing Hui, and Yi Xiao. "Effects of Nano-CeO2 on Microstructure and Properties of WC/FeCoNiCrMo0.2 Composite High Entropy Alloy Coatings by Laser Cladding." Nanomaterials 13, no. 6 (March 19, 2023): 1104. http://dx.doi.org/10.3390/nano13061104.
Full textAbstract:
FeCoNiCrMo0.2 high entropy alloy has many excellent properties, such as high strength, high wear resistance, high corrosion resistance, and high ductility. To further improve the properties of this coating, FeCoNiCrMo high entropy alloy (HEA) coatings, and two composite coatings, FeCoNiCrMo0.2 + WC and FeCoNiCrMo0.2 + WC + CeO2, were prepared on the surface of 316L stainless steel by laser cladding technology. After adding WC ceramic powder and CeO2 rare earth control, the microstructure, hardness, wear resistance, and corrosion resistance of the three coatings were carefully studied. The results show that WC powder significantly improved the hardness of the HEA coating and reduced the friction factor. The FeCoNiCrMo0.2 + 32%WC coating showed excellent mechanical properties, but the distribution of hard phase particles in the coating microstructure was uneven, resulting in unstable distribution of hardness and wear resistance in each region of the coating. After adding 2% nano-CeO2 rare earth oxide, although the hardness and friction factor decreased slightly compared with the FeCoNiCrMo0.2 + 32%WC coating, the coating grain structure was finer, which reduced the porosity and crack sensitivity of the coating, and the phase composition of the coating did not change; there was a uniform hardness distribution, a more stable friction coefficient, and the flattest wear morphology. In addition, under the same corrosive environment, the value of polarization impedance of the FeCoNiCrMo0.2 + 32%WC + 2%CeO2 coating was greater, the corrosion rate was relatively low, and the corrosion resistance was better. Therefore, based on various indexes, the FeCoNiCrMo0.2 + 32%WC + 2%CeO2 coating has the best comprehensive performance and can extend the service life of 316L workpieces.
34
Gao, Pei-Hu, Rui-Tao Fu, Bai-Yang Chen, Sheng-Cong Zeng, Bo Zhang, Zhong Yang, Yong-Chun Guo, et al. "Corrosion Resistance of CoCrFeNiMn High Entropy Alloy Coating Prepared through Plasma Transfer Arc Claddings." Metals 11, no. 11 (November 22, 2021): 1876. http://dx.doi.org/10.3390/met11111876.
Full textAbstract:
High entropy alloy attracts great attention for its high thermal stability and corrosion resistance. A CoCrFeNiMn high-entropy alloy coating was deposited on grey cast iron through plasma transfer arc cladding. It formed fine acicular martensite near the grey cast iron, with columnar grains perpendicular to the interface between the grey cast iron substrate and the cladding layer as well as dendrite in the middle part of the coatings. Simple FCC solid solutions present in the coatings which were similar to the powder’s structure. The coating had a microhardness of 300 ± 21.5 HV0.2 when the cladding current was 80 A for the solid solution strengthening. The HEA coating had the highest corrosion potential of −0.253 V when the plasma current was 60 A, which was much higher than the grey cast iron’s corrosion potential of −0.708 V. Meanwhile, the coating had a much lower corrosion current density of 9.075 × 10−7 mA/cm2 than the grey cast iron’s 2.4825 × 10−6 mA/cm2, which reflected that the CoCrFeNiMn HEA coating had much better corrosion resistance and lower corrosion rate than the grey cast iron for single FCC solid solution phase and a relatively higher concentration of Cr in the grain boundaries than in the grains and this could lead to corrosion protection effects.
35
Ivanov, Yurii F., Yuriy Kh Akhmadeev, Nikita A. Prokopenko, Olga V. Krysina, Nikolai N. Koval, Elizaveta A. Petrikova, Oleg S. Tolkachev, Vladimir V. Shugurov, Vladimir V. Uglov, and Alexander N. Shmakov. "Structure and Properties of NbMoCrTiAl High-Entropy Alloy Coatings Formed by Plasma-Assisted Vacuum Arc Deposition." Coatings 13, no. 7 (July 2, 2023): 1191. http://dx.doi.org/10.3390/coatings13071191.
Full textAbstract:
The paper analyzes the structure and properties of metal, cermet, and ceramic NbMoCrTiAl high-entropy alloy (HEA) coatings formed on solid substrates by plasma-assisted vacuum arc deposition (from multicomponent gas-metal plasma through Nb, Mo, Cr, and TiAl cathode evaporation in argon and/or a mixture of argon and nitrogen). The analysis shows that all coatings represent a nanocrystalline (3–5 nm) multilayer film. The metal coating has a bcc lattice (a = 0.3146 nm). The ceramic coating has an fcc lattice (an uncertain lattice parameter due to highly smeared diffraction peaks). The coating hardness increases in the order of metal, cermet, and then ceramic, reaching 43 GPa at Young’s modulus equal to 326 GPa. When heated in air, the metal and cermet coatings start to oxidize at 630–640 °C, and the ceramic coating at 770–780 °C.
36
DOU, DAN, KUN DENG, and JIANCHEN LI. "MICROSTRUCTURE AND PROPERTIES OF COATING OF AlFeCrNiMo HIGH-ENTROPY ALLOY." Surface Review and Letters 26, no. 03 (March 24, 2019): 1850163. http://dx.doi.org/10.1142/s0218625x18501639.
Full textAbstract:
High-entropy alloys (HEAs) have recently received significant attention in the materials science community. Some of these alloys can display a good combination of mechanical properties. The perfect dense and smooth coatings of AlFeCrNiMo HEA have been deposited by direct current magnetron sputtering method. The coatings possess single BCC crystal structure. The thickness of the coatings increases with increasing deposited time and plasma power. The coatings display excellent high hardness and Young’s modulus. The corrosion resistance of all coatings in acidic and salt media is better than that of 201 stainless steel. It is expected that the HEA coatings have very broad application prospects.
37
Liu, Yusheng, Dingding Xiang, Kaiming Wang, and Tianbiao Yu. "Corrosion of Laser Cladding High-Entropy Alloy Coatings: A Review." Coatings 12, no. 11 (November 3, 2022): 1669. http://dx.doi.org/10.3390/coatings12111669.
Full textAbstract:
Material corrosion is a common phenomenon. Severe corrosion not only causes material failure, but may also lead to unexpected catastrophic accidents. Therefore, reducing the loss caused by corrosion has become a problem faced by countries around the world. As a surface modification technology, laser cladding (LC) can be used to prepare coatings that can achieve metallurgical bonding with the substrate. High-entropy alloys (HEAs) are a new material with superior anti-corrosion ability. Therefore, HEA coatings prepared by LC have become a research hotspot to improve the anti-corrosive ability of material surfaces. In this work, the effects of LC process parameters, post-processing, and the HEA material system on the anti-corrosion ability of HEA coatings and their mechanisms are reviewed. Among them, the LC process parameters influence the anti-corrosion ability by affecting the macroscopic quality, dilution rate, and uniformity of the coatings. The post-processing enhances the anti-corrosion ability of the coatings by improving the internal defects and refining the grain structure. The anti-corrosion ability of the coatings can be improved by appropriately adding transition metal elements such as Ni, Cr, Co, and rare earth elements such as Ce and Y. However, the lattice distortion, diversification of phase composition, and uneven distribution caused by excess elements will weaken the corrosion protection of the coatings. We reviewed the impact of corrosion medium on the anti-corrosion ability of coatings, in which the temperature and pH value of the corrosion medium affect the quality of the passive film on the surface of the coatings, thereby affecting the anti-corrosion ability of the coatings. Finally, to provide references for future research, the development trend of preparing HEA coatings by LC technology is prospected.
38
Wu, Tao, Yunxiang Chen, Shuqin Shi, Mengting Wu, Wanyuan Gui, Yuanyuan Tan, Jiheng Li, and Yuan Wu. "Effects of W Alloying on the Lattice Distortion and Wear Behavior of Laser Cladding AlCoCrFeNiWx High-Entropy Alloy Coatings." Materials 14, no. 18 (September 21, 2021): 5450. http://dx.doi.org/10.3390/ma14185450.
Full textAbstract:
Friction and wear properties of hot working die steel at above 800 °C are of particular interest for high temperature applications. Here, novel AlCoCrFeNiWx high-entropy alloy (HEA) coatings have been fabricated on the surface of hot working die steel by laser cladding. The effects of the as-prepared AlCoCrFeNiWx HEA coatings on the microstructure and high temperature friction and wear behavior of hot working die steel are investigated through scanning electron microscopy (SEM), electron probe microanalysis (EPMA), X-ray diffraction (XRD), and X-ray absorption fine structure (XAFS). Having benefited from the formation of W-rich intermetallic compounds after the addition of W elements, the high temperature wear resistance of the coatings is obviously improved, and friction coefficient shows a large fluctuation. The microstructural characteristics of the AlCoCrFeNiWx HEA coatings after the high temperature wear resistance test shows a highly favorable impact on microstructure stability and wear resistance, due to its the strong lattice distortion effect of W element on BCC solid solutions and the second phase strengthening of the W-rich intermetallic compounds. These findings may provide a method to design the high temperature wear resistant coatings.
39
Wu, Tao, Yunxiang Chen, Bo Lin, Litao Yu, Wanyuan Gui, Jiheng Li, Yuan Wu, and Dawen Zeng. "Effects of WC on the Microstructure, Wear and Corrosion Resistance of Laser-Deposited CoCrFeNi High Entropy Alloy Coatings." Coatings 12, no. 7 (July 12, 2022): 985. http://dx.doi.org/10.3390/coatings12070985.
Full textAbstract:
Wear and corrosion resistant properties of high entropy alloy coatings (HEAC) on H13 steel are of particular interest for industrial applications. The CoCrFeNi HEA/WC composite coatings (HEACC) developed in this study were successfully prepared by incorporating 10–40 wt.% WC into a matrix of CoCrFeNi HEA using laser cladding on an H13 steel substrate. Phase transformation, microstructure evolution, microhardness, wear and corrosion resistance of CoCrFeNi HEACC were investigated. According to the results, all CoCrFeNi HEACC exhibited higher wear and corrosion resistance than the H13 steel substrate. Wear resistance of CoCrFeNi HEACC first increases and then decreases with an increase in the concentration of WC particles, and the lowest coefficient of friction and the shallowest depth of wear groove were observed after adding 30 wt.%. Grain refinement strengthening and second-phase particle strengthening may contribute to enhanced hardness and wear resistance of coatings with WC additions. In addition, all the CoCrFeNi HEACC exhibited improved corrosion resistance. In particular, an addition of 10 wt.% WC helped to significantly improve the corrosion resistance and ease of passivation of CoCrFeNi HEACC.
40
Liu, Jianjun, Kai Ma, Yutian Ding, Li Feng, Wensheng Li, and Lingyu Li. "Microstructure and Properties of an FeCoCrAlCu HEA Coating Synthesized via the Induction Remelting Method." Coatings 13, no. 2 (February 9, 2023): 399. http://dx.doi.org/10.3390/coatings13020399.
Full textAbstract:
An FeCoCrAlCu HEA coating was prepared on the surface of 45# steel by cold-spray-assisted induction remelting. The results showed that the FeCoCrAlCu HEA coating was composed of BCC and FCC phases. The BCC phase possessed an amplitude-modulated structure consisting of a B1-disordered phase (FeCr) and a B2-ordered phase (AlCo), as well as a nanoscale BCC phase precipitated near grain boundaries. The FCC phase was composed of a solid solution of the Al–Cu matrix and manifested characteristics of a typical twin structure. In addition, the hardness of the FeCoCrAlCu HEA coating was 528.2 HV. The friction coefficient of the FeCoCrAlCu HEA-/Al2O3 pair was 0.379, and the wear rate was 3.96 × 10−5 mm3/(N × m). In 3.5 wt.%NaCl and 5.0 wt.%H2SO4 corrosive media, the FeCoCrAlCu HEA coating had a more positive self-corrosion potential (Ecorr) and a lower corrosion current density (Icorr) than the substrate.
41
Li, Yaning, Hui Liang, Qiuxin Nie, Zhaoxin Qi, Dewei Deng, Hui Jiang, and Zhiqiang Cao. "Microstructures and Wear Resistance of CoCrFeNi2V0.5Tix High-Entropy Alloy Coatings Prepared by Laser Cladding." Crystals 10, no. 5 (April 29, 2020): 352. http://dx.doi.org/10.3390/cryst10050352.
Full textAbstract:
CoCrFeNi2V0.5Tix high entropy alloy coatings were synthesized by laser cladding on Ti-6Al-4V (annotated as TC4) substrate. The microstructures, hardness, and wear properties of the coatings were studied in detail. The results showed that these coatings were all composed of body-centered cubic (BCC) solid solution, (Co,Ni)Ti2 phase, and Ti-rich phase. With the increase of Ti content (x in the range of 0–1.0), the hardness of these coatings (about 960 HV) was basically unchanged and stabilized, whereas, when x was increased to 1.25, the correspondent hardness was decreased significantly to about 830 HV. Compared with original substrate, the wear resistance of high-entropy alloy (HEA) coatings was greatly improved. In particular, CoCrFeNi2V0.5Ti0.75 (donated as Ti0.75) exhibited the lowest wear rate, width, and depth of tracks of wear, indicating the best wear resistance. Moreover, the wear mechanisms of Ti0.75 coating were mainly adhesive wear and oxidative wear.
42
Gite, Vikas V., and Ashok B. Chaudhari. "Incorporation of Modified Nano Montmorillonite (MMT) in Polyurethane Coatings Based on Acrylic Copolymer and Trimer of Isophorone Diisocyanate." Materials Science Forum 757 (May 2013): 99–109. http://dx.doi.org/10.4028/www.scientific.net/msf.757.99.
Full textAbstract:
This work presents the synthesis of acrylic copolymer and trimer of isophorone diisocyanate (IPDI) for preparation of polyurethane (PU) coatings. Further we have studied the effect of silane modified nano montmorillonite (MMT) on the properties of PU coatings. Nano MMT was modified by vinyltriethoxysilane (TEVS) coupling agent and incorporated in PU coatings made from acrylic copolymers and trimer of IPDI. Acrylic copolymer was synthesized in the laboratory using butyl acrylate (BA), methyl methacrylate (MMA), styrene and hydroxyl ethyl acrylate (HEA) monomers. Coating properties of prepared PU coatings studied are gloss, impact resistance, flexibility, cross hatch adhesion and physicochemical properties include chemical resistance. The experimental results revealed that polyurethane coatings based on MMT based acrylic polyol and IPDI trimer showed good gloss and excellent adhesion. Thermal stability of these PU samples was found upto 229 °C. Physicochemical properties reflected that these PU have excellent chemical and solvent resistance.
43
Novikov, Vseslav, Nikita Stepanov, Sergey Zherebtsov, and Gennady Salishchev. "Structure and Properties of High-Entropy Nitride Coatings." Metals 12, no. 5 (May 16, 2022): 847. http://dx.doi.org/10.3390/met12050847.
Full textAbstract:
The interest in nitride coatings based on high-entropy alloys (HEAs) has increased rapidly in the last decade. According to a number of papers, such high-entropy nitride (HEN) coatings have a single-phase structure and properties that significantly exceed those of simpler nitride systems. These properties include high hardness, wear resistance, oxidation resistance and thermal stability. It is believed that these distinctive properties are due to the high entropy of mixing, which increases with an increase in the number of elements in the composition. However, comparison with various binary and ternary systems shows that better properties are not typical of each HEA-based coating, and the effect of the number of elements competes with other factors that can make even more pronounced contributions to the structure and properties of the coating. Because of fragmentation of data on the structure and properties of high-entropy coatings, a unified concept of alloying is needed. This review compares the methods for obtaining HEN coatings, describes their structural features and analyzes the main properties, such as hardness, wear resistance and oxidation resistance, in order to establish an understanding of the influence of the number of elements and their role in the composition of coatings.
44
Eremin, Evgeniy N., Sergey A. Guchenko, and Viktor M. Yurov. "Application of Multi-Element Targets for the Formation of High Entropy Coatings." Defect and Diffusion Forum 410 (August 17, 2021): 501–6. http://dx.doi.org/10.4028/www.scientific.net/ddf.410.501.
Full textAbstract:
The development of modern technologies in various industries cannot be imagined without the development and use of new materials, including new highly entropic alloys (HEA) and coatings based on them, as more advanced in terms of performance compared to traditional materials and coatings. Methods for producing various highly entropic alloys are described in many literature. Almost all such technologies at the moment cannot be applicable in the mass production of parts due to the high cost and lack of appropriate infrastructure and production technologies. However, obtaining coatings formed on the basis of highly entropic alloys for various parts of mechanisms and machines is currently a highly promising direction in improving the operational properties of work surfaces. The goal of this work is to create highly entropic coatings obtained by magnetron sputtering of special multicomponent targets. The paper shows the possibility of synthesis of coatings of the predicted composition and properties. A coating based on a matrix target made of 12Kh18N10T steel with pressed multicomponent Cr-Ni-Zr-Ti-Cu pellets was synthesized. The elemental composition of the coating and its properties were determined, the microhardness was measured, and the functional properties were established.
45
Mehmood, Kashif, Malik Adeel Umer, Ahmed Umar Munawar, Muhammad Imran, Muhammad Shahid, Muhammad Ilyas, Rabeeka Firdous, Humaira Kousar, and Muhammad Usman. "Microstructure and Corrosion Behavior of Atmospheric Plasma Sprayed NiCoCrAlFe High Entropy Alloy Coating." Materials 15, no. 4 (February 16, 2022): 1486. http://dx.doi.org/10.3390/ma15041486.
Full textAbstract:
High entropy alloys (HEAs) are multi-elemental alloy systems that exhibit a combination of exceptional mechanical and physical properties, and nowadays are validating their potential in the form of thermal sprayed coatings. In the present study, a novel synthesis method is presented to form high entropy alloy coatings. For this purpose, thermal sprayed coatings were deposited on Stainless Steel 316L substrates using atmospheric plasma spraying technique with subsequent annealing, at 1000 °C for 4 h, to assist alloy formation by thermal diffusion. The coatings in as-coated samples as well as in annealed forms were extensively studied by SEM for microstructure and cross-sectional analysis. Phase identification was performed by X-ray diffraction studies. The annealed coatings revealed a mixed BCC and FCC based HEA structure. Potentiodynamic corrosion behavior of SS316L sprayed as well as annealed coatings were also carried out in 3.5% NaCl solution and it was found that the HEA-based annealed coatings displayed the best corrosion resistance 0.83 (mpy), as compared to coated/non-annealed and SS 316 L that showed corrosion resistance of 7.60 (mpy) and 3.04 (mpy), respectively.
46
Souto, Carlos Alberto, Gustavo Faria Melo da Silva, Laura Angelica Ardila Rodriguez, Aline C. de Oliveira, and Kátia Regina Cardoso. "Laser Assisted High Entropy Alloy Coating on Low Carbon Steel." Key Engineering Materials 813 (July 2019): 159–64. http://dx.doi.org/10.4028/www.scientific.net/kem.813.159.
Full textAbstract:
Coatings with high entropy alloys of the AlCoCrFeNiV system were obtained by selective laser melting on low carbon steel substrates. The effect of the variation of the Fe and V contents as well as the laser processing parameters in the development of the coating were evaluated. The coatings were obtained from the simple powder mixtures of the high purity elemental components in a planetary ball mill. The coatings were obtained by using CO2 laser with a power of 100 W, diameter of 0.16 mm, and scan speed varying from 3 to 12 mm/s. Phase constituents, microstructure and hardness were investigated by XRD, SEM, and microhardness tester, respectively. Wear resistance measurements were carried out by the micro-abrasion method using ball-cratering tests. The coatings presented good adhesion to the substrate and high hardness, of the order of 480 to 650 HV. Most homogeneous coating with nominal composition was obtained by using the higher scan speed, 12 mm/s. Vanadium addition increased hardness and gave rise to a high entropy alloy coating composed by BCC solid solutions. Ball cratering tests conducted on HEA layer showing improvement of material wear resistance, when compared to base substrate, decreasing up to 88% its wear rate, from 1.91x10-6 mm3/Nmm to 0.23x10-6 mm3/Nmm.
47
Devarajan, Dinesh Kumar, Baskaran Rangasamy, and Kamalan Kirubaharan Amirtharaj Mosas. "State-of-the-Art Developments in Advanced Hard Ceramic Coatings Using PVD Techniques for High-Temperature Tribological Applications." Ceramics 6, no. 1 (January 21, 2023): 301–29. http://dx.doi.org/10.3390/ceramics6010019.
Full textAbstract:
Hard and wear-resistant coatings created utilizing physical vapor deposition (PVD) techniques are extensively used in extreme tribological applications. The friction and wear behavior of coatings vary significantly with temperature, indicating that advanced coating concepts are essential for prolonged load-bearing applications. Many coating concepts have recently been explored in this area, including multicomponent, multilayer, gradient coatings; high entropy alloy (HEA) nitride; and functionally modified coatings. In this review, we highlighted the most significant findings from ongoing research to comprehend crucial coating properties and design aspects. To obtain enhanced tribological properties, the microstructure, composition, residual stress, hardness, and HT oxidation resistance are tuned through doping or addition of appropriate materials at an optimized level into the primary coatings. Such improvements are achieved by optimizing PVD process parameters such as input power, partial pressure, reactive gas flow rates, substrate bias, and temperature. The incorporation of ideal amounts of Si, Cr, Mo, W, Ag, and Cu into ternary and quaternary coatings, as well as unique multilayer designs, considerably increases the tribological performance of the coatings. Recent discoveries show that not only mechanical hardness and fracture toughness govern wear resistance, but also that oxidation at HT plays a significant role in the lubrication or wear failure of coatings. The tribo-induced metal oxides and/or Magnéli phases concentrated in the tribolayer are the key governing factors of friction and wear behavior at high temperatures. This review includes detailed insights into the advancements in wear resistance as well as various failure mechanisms associated with temperature changes.
48
Gao, Yang, Zihan Yang, Haibo Xiao, Qian Lei, Bin Liu, and Yong Liu. "Effect of Welding Current on Wear Behavior of PTA-Welded Cu35Ni25Co25Cr15 HEA Coating." Coatings 13, no. 1 (December 28, 2022): 52. http://dx.doi.org/10.3390/coatings13010052.
Full textAbstract:
High-entropy alloys (HEAs) have received increasing attention because of their excellent properties. To improve the surface hardness and wear resistance of pure Cu, a Cu35Ni25Co25Cr15 HEA coating was, for the first time, deposited on a pure Cu substrate by plasma transfer arc (PTA) welding. The welding current varied from 130 to 160 A. The microstructures and mechanical properties of the coating were investigated. The Cu35Ni25Co25Cr15 HEA coating comprised face-cubic-centered A1 (Cu-rich) and γ′ (NiCoCr-rich) phases. The coating had an apparent structural gradient with coarse grains at the interface with the Cu substrate. The bottom, middle, and top zones of the coating exhibited a fine smooth cellular structure, fine-needle structure, and long dendrites, respectively. As the welding current was increased, the dilution ratio of the coating and interfacial bonding strength gradually increased, whereas the hardness of the coating increased and then decreased. Under a welding current of 150 A, no gaps or pores appeared in the interface, and the coating exhibited good metallurgical bonding with the Cu substrate. The wear mechanisms of the Cu35Ni25Co25Cr15 HEA coating at different temperatures were also determined. Compared with pure Cu, the Cu35Ni25Co25Cr15 HEA coating exhibited excellent wear resistance, especially at high temperatures. This study paves a new way for coating on pure Cu and enhances the wear resistance of Cu components.
49
Xu, Juan, Shouren Wang, Caiyun Shang, Shifeng Huang, and Yan Wang. "Microstructure and Properties of CoCrFeNi(WC) High-Entropy Alloy Coatings Prepared Using Mechanical Alloying and Hot Pressing Sintering." Coatings 9, no. 1 (December 28, 2018): 16. http://dx.doi.org/10.3390/coatings9010016.
Full textAbstract:
The CoCrFeNi high-entropy alloy coatings (HEACs) with different weight ratios (10 and 30 wt.%) of WC additions have been prepared using mechanical alloying and a vacuum hot pressing sintering technique on a Q235 steel substrate. The microstructures, microhardness, wear resistance, and corrosion resistance of HEACs were studied. The CoCrFeNi(WC) powders were obtained by mixing the CoCrFeNi HEA powders and WC particles. The sintered products of both HEACs with high relative density contained one solid solution phase with face-centered cubic structure, WC, and unknown precipitate phases. The transition boundary had a good metallurgical bonding with the coating and substrate. The average microhardness values of CoCrFeNi HEACs with 10 and 30 wt.% WC additions reached 475 and 531 HV respectively, which were far higher than that of the substrate (160 HV). Moreover, both coatings exhibited better wear resistance than the substrate under the same wear conditions. The 30 wt.% WC HEAC displayed the lower friction coefficient, and the shallower wear groove depth. The grain refinement strengthening and second-phase particle strengthening could be beneficial to the enhanced hardness and wear resistance of coatings with WC additions. The corrosion behavior of the tested samples in the 3.5 wt.% NaCl solution were investigated using electrochemical polarization measurements. The CoCrFeNi(WC) coatings all revealed the improved corrosion resistance. Especially, a 10 wt.% WC addition remarkably enhanced the comprehensive corrosion resistance and easy passivation of CoCrFeNi HEAC.
50
Chang, Yin-Yu, and Cheng-Hsi Chung. "Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings." Coatings 11, no. 1 (January 2, 2021): 41. http://dx.doi.org/10.3390/coatings11010041.
Full textAbstract:
Multi-element material coating systems have received much attention for improving the mechanical performance in industry. However, they are still focused on ternary systems and seldom beyond quaternary ones. High entropy alloy (HEA) bulk material and thin films are systems that are each comprised of at least five principal metal elements in equally matched proportions, and some of them are found possessing much higher strength than traditional alloys. In this study, CrVTiNbZr high entropy alloy and nitrogen contained CrVTiNbZr(N) nitride coatings were synthesized using high ionization cathodic-arc deposition. A chromium-vanadium alloy target, a titanium-niobium alloy target and a pure zirconium target were used for the deposition. By controlling the nitrogen content and cathode current, the CrNbTiVZr(N) coating with gradient or multilayered composition control possessed different microstructures and mechanical properties. The effect of the nitrogen content on the chemical composition, microstructure and mechanical properties of the CrVTiNbZr(N) coatings was investigated. Compact columnar microstructure was obtained for the synthesized CrVTiNbZr(N) coatings. The CrVTiNbZrN coating (HEAN-N165), which was deposited with nitrogen flow rate of 165 standard cubic centimeters per minute (sccm), exhibited slightly blurred columnar and multilayered structures containing CrVN, TiNbN and ZrN. The design of multilayered CrVTiNbZrN coatings showed good adhesion strength. Improvement of adhesion strength was obtained with composition-gradient interlayers. The CrVTiNbZrN coating with nitrogen content higher than 50 at.% possessed the highest hardness (25.2 GPa) and the resistance to plastic deformation H3/E*2 (0.2 GPa) value, and therefore the lowest wear rate was obtained because of high abrasion wear resistance.