Статті в журналах: "Ni-P alloy coatings"

1

Sahoo, Prasanta, and Supriyo Roy. "Tribological Behavior of Electroless Ni-P, Ni-P-W and Ni-P-Cu Coatings." International Journal of Surface Engineering and Interdisciplinary Materials Science 5, no. 1 (January 2017): 1–15. http://dx.doi.org/10.4018/ijseims.2017010101.

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The present paper considers the comparative study of tribological characteristics of various electroless alloy coatings viz. Ni-P, Ni-P-W and Ni-P-Cu. The tribological behavior of these coatings depends on various parameters like load, speed, lubricant, chemical compositions and heat treatment temperature to a great extent. One of the main effects of heat treatment on these coatings is phosphide precipitation, which makes them suitable for anti-wear applications. The property of binary Ni-P can be further improved by depositing third particles electrolessly. The phase structure of the coatings depends on the amount of phosphorous and heat treatment temperature. The tribological behavior of heat treated samples reveals that Ni-P-W deposit shows higher coefficient of friction and lowest wear among these three types coatings. Very high tungsten concentration retard the phosphide precipitation, thus low concentration of tungsten and low heat treatment temperature produce better coating. In case of Ni-P-Cu, medium concentration of copper and medium heat treatment temperature produces better coating.

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2

Hou, Jun Ying, Song Rui Wang, and Zhi Wei Zhou. "The Effect of Ni-P Alloy Pre-Plating on the Performance of Ni-P/Ni-P-PTFE Composite Coatings." Key Engineering Materials 561 (July 2013): 537–41. http://dx.doi.org/10.4028/www.scientific.net/kem.561.537.

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In order to obtain more excellent performance of composite coating, a layer of Ni-P alloy was plated firstly, then Ni-P-PTFE composite coatings was plated. If plating time ratio of electroless plating Ni-P alloy and Ni-P-PTFE composite plating was properlly controlled, performance of pure Ni-P-PTFE composite coating could be improved. The study have shown that the total plating time is 2 hours, and the plating time ratio is 1:1, and good bonding strength with the substrate, right hardness, low friction coefficient, good corrosion resistance of Ni-P /Ni-P-PTFE composite coatings have been obtained.

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3

Łosiewicz, Bożena, Magdalena Popczyk, and Patrycja Osak. "New Ni-Me-P Electrode Materials." Solid State Phenomena 228 (March 2015): 39–48. http://dx.doi.org/10.4028/www.scientific.net/ssp.228.39.

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The Ni-Me-P alloy coatings containing metal as alloying component (Me = Co, W) in a Ni-P amorphous matrix, were potentiostatically electrodeposited onto a polycrystalline Cu substrate. Deposition potential was established based on polarization curves of electrodeposition of Ni-Co-P, Ni-W-P and Ni-P alloy coatings. SEM, EDS, XRD and X-ray microanalysis methods, were applied for chemical and physical characterization of the obtained coatings. Linear analysis of Ni, Co and W distribution in the microregions of the appropriate alloy coating revealed that surface distribution of these elements is homogeneous what is due to a molecular mixing of the amorphous nickel matrix with the alloying components. It was found that the Ni-Co-P and Ni-W-P coatings have the amorphous structure like the Ni-P deposit and alloying components as Co or W are built-in into the appropriate coating in the amorphous form. The mechanism of the induced codeposition of these ternary Ni-Me-P coatings, has been discussed.

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4

Huang, Hao-Hsiang, Fan-Bean Wu, Jyh-Wei Lee, and Li-Chun Chang. "Microstructure and Corrosion Behavior of Ni-Alloy/CrN Nanolayered Coatings." Journal of Nanomaterials 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/137498.

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The Ni-alloy/CrN nanolayered coatings, Ni-Al/CrN and Ni-P/CrN, were deposited on (100) silicon wafer and AISI 420 stainless steel substrates by dual-gun sputtering technique. The influences of the layer microstructure on corrosion behavior of the nanolayered thin films were investigated. The bilayer thickness was controlled approximately 10 nm with a total coating thickness of . The single-layer Ni-alloy and CrN coatings deposited at were also evaluated for comparison. Through phase identification, phases of Ni-P and Ni-Al compounds were observed in the single Ni-alloy layers. On the other hand, the nanolayered Ni-P/CrN and Ni-Al/CrN coatings showed an amorphous/nanocrystalline microstructure. The precipitation of Ni-Al and Ni-P intermetallic compounds was suppressed by the nanolayered configuration of Ni-alloy/CrN coatings. Through Tafel analysis, the and values ranged from –0.64 to –0.33 V and to A/, respectively, were deduced for various coating assemblies. The corrosion mechanisms and related behaviors of the coatings were compared. The coatings with a nanolayered Ni-alloy/CrN configuration exhibited a superior corrosion resistance to single-layer alloy or nitride coatings.

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5

Mao, Guo Bing. "Fast Electroless Ni-P Coating on AM60 Magnesium Alloy at Low Bath Temperature." Advanced Materials Research 418-420 (December 2011): 756–59. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.756.

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The Ni-P coatings were deposited on AM60 magnesium alloy by electroless plating process without or with accelerators. Without accelerators, the deposition rate is slow and required high bath temperature to obtain compact coating. There have many defects on the surface of the Ni-P coatings which deposited at high bath temperature. The composite accelerators were introduced into the bath for improving the growth rate and the quality of the Ni-P coating. Uniform, with no pores or cracks, “cauliflower-like” structure and complete Ni-P coatings were deposited only taken 20 min with additives at low bath temperature. The XRD result indicates that the structure of the Ni-P coating is amorphous nickel. The corrosion test results indicated that the corrosion resistance of this coated AM60 magnesium alloys increases distinctly as compared to bare alloys.

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6

Chou, Yu Hsien, Ching Yuan Bai, Ming Der Ger, Shuo Jen Lee, Chi Yuan Lee, and Chu Lung Chao. "Studies on Ni-Mo-P Coatings by Electroless Deposition." Key Engineering Materials 364-366 (December 2007): 333–39. http://dx.doi.org/10.4028/www.scientific.net/kem.364-366.333.

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This paper describes the performance of Ni-P and Ni-Mo-P alloy coatings deposited by electroless plating on the aluminum alloy 5052 to evaluate the corrosion resistance, thermal stability and electro-conductivity of coating assemblies. Corrosion behaviors of the obtained deposits in a 0.5M H2SO4 environment were investigated. The crystalline state and morphologies of Ni-P and Ni- Mo-P alloys were examined by field emission scanning electron microscopy (FE-SEM). The experimental results indicate that the Ni-Mo-P coating operated at 70°C and pH 9.0 has a nanocrystalline structure and its corrosion resistance in a 0.5M H2SO4 environment can be enhanced by the co-deposition of Mo as compared to Ni-P films. It has also been found that the Ni-Mo-P ternary alloys reveal good thermal stability after annealing at 400°C. Based on the excellent performance of Ni-Mo-P ternary alloys, these alloys have a potential to be applied to precision mould, optical parts mould, and surface metallization of substrates.

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7

Lee, Cheng Kuo, Chi Lun Teng, An Hung Tan, Ching Yi Yang, and Sheng Long Lee. "Electroless Ni-P/Diamond/Graphene Composite Coatings and Characterization of their Wear and Corrosion Resistance in Sodium Chloride Solution." Key Engineering Materials 656-657 (July 2015): 51–56. http://dx.doi.org/10.4028/www.scientific.net/kem.656-657.51.

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The purpose of the present study is to evaluate the effect of the electroless Ni-P/diamond/graphene composite coating on the structure and surface hardness of 2024-T6 aluminum alloy as well as their effect on the corrosion and wear resistance of the alloy in 3.5 % NaCl solution. The electroless Ni-P plating solution was prepared by adding different size diamond (6-12 μm and 0.2 μm) and nanographene into the electroless Ni-P plating solution to obtain Ni-P/diamond, Ni-P/graphene and Ni-P/daimond/graphene composite coatings for comparison. Experimental results indicated that the Ni-P/diamond, Ni-P/graphene and Ni-P/daimond/graphene composite coatings can be successfully electroless deposited on anodized 2024-T6 aluminum alloy. The anodically oxidized films, that formed on the aluminum alloy using phosphoric acid as the electrolyte, was porous with high density of pores, and thus could enhance the adhesion of the composite coatings. The Ni-P/daimond/graphene hybrid coating had a higher hardness as well as better corrosion and wear resistance of 2024-T6 alloy in 3.5 wt.% NaCl solution as compared with other composite coatings. When the combination of nanographene and smaller diamond particles added this beneficial effect was significantly raised, especially the composite coating was further vacuum annealed at 400 °C for 24 h to obtain a more smooth and defect-free coating structure.

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8

Rattanawaleedirojn, Pranee, Kanokwan Saengkiettiyut, Yuttanant Boonyongmaneerat, and Jumpot Wanichsampan. "Factors Affecting on the Corrosion Resistance of Electroless Ni-Zn-P Coated Steel." Key Engineering Materials 751 (August 2017): 125–30. http://dx.doi.org/10.4028/www.scientific.net/kem.751.125.

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Electroless Ni-Zn-P coating with the optimal content of Ni and Zn in the alloy provides high corrosion resistance for steel. Ni-rich phase of this high hardness Ni-Zn-P alloy offers barrier protection property and sacrificial protection property is obtained from the alloy with proper content of Zn. In this work, the Ni-Zn-P coatings were prepared on steel substrates by using alkaline electroless deposition. The parameters of deposition process including complexing agent concentration, bath pH, zinc ion and nickel ion concentration were systematically studied. The microstructural morphology and elemental composition of the coatings were characterized by scanning electron microscopy. It was found that complexing agent, zinc ion and nickel ion concentrations play important role on Zn content of Ni-Zn-P alloy whereas alkalinity of the solution bath directly affects the deposition rate. The results of corrosion resistance investigated by linear polarization illustrate that the corrosion potential (Ecorr) of Ni-Zn-P coatings is negatively shifted by an increase of Zn content in the alloys. From this work, Ecorr of 83%Ni-11%Zn-6%P coating prepared in this system is slightly lower than steel. To achieve a higher effect of sacrificial protection for corrosion protection of steel, Ni-Zn-P with higher content of Zn should be further studied.

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9

Narayan, Raj, and M. N. Mungole. "Electrodeposition of Ni-P alloy coatings." Surface Technology 24, no. 3 (March 1985): 233–39. http://dx.doi.org/10.1016/0376-4583(85)90073-1.

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10

Wasserbauer, Jaromír, Martin Buchtík, Jakub Tkacz, Stanislava Fintová, Jozef Minda, and Leoš Doskočil. "Improvement of AZ91 Alloy Corrosion Properties by Duplex NI-P Coating Deposition." Materials 13, no. 6 (March 17, 2020): 1357. http://dx.doi.org/10.3390/ma13061357.

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The corrosion behavior of duplex Ni-P coatings deposited on AZ91 magnesium alloy was studied. The electroless deposition process of duplex Ni-P coating consisted in the preparation of low-phosphorus Ni-P coating (5.7 wt.% of P), which served as a bond coating and high-phosphorus Ni-P coating (11.5 wt.% of P) deposited on it. The duplex Ni-P coatings with the thickness of 25, 50, 75 and 100 µm were deposited on AZ91 magnesium alloy. The electrochemical corrosion behavior of coated AZ91 magnesium alloy was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization method in 0.1 M NaCl. Obtained results showed a significant improvement in the corrosion resistance of coated specimens when compared to uncoated AZ91 magnesium alloy. From the results of the immersion tests in 3.5 wt.% NaCl, 10% solution of HCl and NaOH and 5% neutral salt spray, a noticeable increase in the corrosion resistance with the increasing thickness of the Ni-P coating was observed.

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11

Mabrouk, Ahmed, and Zoheir Farhat. "Novel Ni-P-Tribaloy Composite Protective Coating." Materials 16, no. 11 (May 25, 2023): 3949. http://dx.doi.org/10.3390/ma16113949.

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Oil and gas pipelines are subject to various forms of damage and degradation during their operation. Electroless Nickel (Ni-P) coatings are widely employed as protective coatings due to their ease of application and unique properties, including high wear and corrosion resistance. However, they are not ideal for protecting pipelines due to their brittleness and low toughness. Composite coatings of higher toughness can be developed through the co-deposition of second-phase particles into the Ni-P matrix. Tribaloy (CoMoCrSi) alloy possesses excellent mechanical and tribological properties making it a potential candidate for a high-toughness composite coating. In this study, Ni-P-Tribaloy composite coating consisting of 15.7 vol.% Tribaloy was successfully deposited on low-carbon steel substrates. Both the monolithic and the composite coatings were studied to evaluate the effect of the addition of Tribaloy particles. The micro-hardness of the composite coating was measured to be 6.00 GPa, 12% greater than that of the monolithic coating. Hertzian-type indentation testing was carried out to investigate the coating’s fracture toughness and toughening mechanisms. The 15.7 vol.% Tribaloy coating exhibited remarkably less severe cracking and higher toughness. The following toughening mechanisms were observed: micro-cracking, crack bridging, crack arrest, and crack deflection. The addition of the Tribaloy particles was also estimated to quadruple the fracture toughness. Scratch testing was performed to evaluate the sliding wear resistance under a constant load and a varying number of passes. The Ni-P-Tribaloy coating exhibited more ductile behavior and higher toughness, as the dominant wear mechanism was identified as material removal, as opposed to brittle fracture in the Ni-P coating.

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12

Zhu, Li Qun, Yan Bin Du, Zhen Xue, and Ying Xu Li. "Structure and Anti-Corrosion of Tri-Layer Ni-P Amorphous Alloy Coating Prepared in the Same Bath." Materials Science Forum 546-549 (May 2007): 1805–8. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.1805.

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A tri-layer amorphous Ni-P alloy coating was prepared in the same bath by changing the temperatures and currents, followed by heat treament. We studied the behavior of corrosion-resistance of the tri-layer coating before and after heat-treatment at 360°C for different time in the 5% NaCl solution. The result showed that: the tri-layer amorphous Ni-P coating has the excellent performance of anti-corrosion compare with single electroless or electrodeposited Ni-P amorphous coating. The performance of anti-corrosion of the coating was improved by controlling the coating’s structure and the role of electrochemical protection. After being heat-treated at 360°C for 1 hour ,the coating’s structure changed from amorphous to crystalloid and the corrosion resistance of the heat-treated coatings was higher than as-plated tri-layer Ni-P coating.

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13

Zaimi, M., M. N. Azran, M. S. Kasim, M. R. M. Kamal, I. S. Othman, K. T. Lau, T. D. Widodo, and A. H. Sofian. "Effect of heat treatment on the tribological performance of electroless quaternary nickel alloy." Journal of Mechanical Engineering and Sciences 13, no. 3 (September 27, 2019): 5637–52. http://dx.doi.org/10.15282/jmes.13.3.2019.26.0452.

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Heat treatment of nickel-based alloy can increase the alloy’s hardness as well as the wear resistance properties. Nevertheless, the effect of heat treatment on the quaternary Ni alloy coating properties produced from electroless deposition bath is less known due to its composition uniqueness. In this study, Cu and Co are added in the Ni-P alloy matrix using hypophosphite-based Electroless Ni deposition method on mild steel substrate in acidic and alkaline bath. The coatings are then heat treated at 623 K for 3600s. The coatings hardness is measured using microVickers hardness tester and the surface morphology of the coatings are studied using both Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis. X-ray fluorescence (XRF) measurement is used to measure the coatings compositions. The wear behavior of the coatings is also investigated before and after heat treatment using ASTM G-99. The coatings from acidic-based bath produces Ni-Cu-Co-P alloy coating while the alkaline-based bath produces Ni-Co-Cu-P alloy based on XRF analysis. Results show that the hardness increases more than 20% for acidic-based bath and 40% for alkaline-based bath coating. The highest increment is the Ni-Co-Cu-P alloy, from 553.3 HV to 991.3 HV after heat treatment. The grain refinement of the coatings can be observed after heat treatment in SEM observation. This is proved by the XRD measurement results where polycrystalline Ni (111) formation is seen after heat treatment overshadowing the Cu (111) and Co (111) peaks. Ni phosphide species are also formed after the heat treatment. The polycrystalline Ni and the Ni phosphide formation, as well as the existence of Co and Cu in the alloy deposits reduces the wear rate significantly after the heat treatment.

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14

Wu, Li Ping, Zhong Dong Yang, Jing Jing Zhao, and Yong Ping Xie. "A Novel Electroless Ni-P Deposition on AZ91D Magnesium Alloy." Advanced Materials Research 154-155 (October 2010): 1330–35. http://dx.doi.org/10.4028/www.scientific.net/amr.154-155.1330.

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Currently, most of electroless nickel phosphorus plating on magnesium alloys has following disadvantages. First, it has been suffering from corrosion issues caused by acidic electroless bath. Second, in order to increase the strength of Ni-P coatings to the Mg substrate, the pretreatments for electroless Ni-P employ hydrofluoric acid (HF) and hexavalent chromium (Cr6+) which can cause pollution and health problems . In this paper, we developed HF-free and alkaline electroless Ni-P deposition process on AZ91D magnesium alloy which avoids the use of SO42- and Cl- ions in the electroless plating bath, thus leading to good adhesion and corrosion resistance of electroless Ni-P coating on magnesium alloy. XRD, SEM, EDS techniques were used to study the structure, morphology, and chemical compositions of the conversion coating and Ni-P coating, respectively. Polarization measurements indicated that the corrosion rate of Ni-P coated Mg was six times lower than that of bare Mg. Electrochemical impedance spectroscopy (EIS) also showed that the Ni-P coating could effectively protect Mg alloy from corrosion.

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15

Li, Yongfeng, Kun Zhang, Mingming Zhang, Tingting Wu, Peng Cao, and Wei Gao. "Preparation of electroless Ni-P alloy coating with medium temperature and low phosphorus content." International Journal of Modern Physics B 34, no. 01n03 (December 16, 2019): 2040044. http://dx.doi.org/10.1142/s0217979220400445.

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Low phosphorus electroless Ni-P alloy coating has many advantages over medium and high phosphorus electroless Ni-P alloy coatings because of its special microstructure and composition, which can meet more special performance requirements. In addition, reducing the plating temperature can reduce energy consumption. The preparation process of electroless Ni-P plating at medium temperature and low-P was studied by single factor and orthogonal experiment. The results show that electroless Ni-P alloy coatings with 4–6% P can be obtained at 60–80[Formula: see text]C and pH=5–6. The hardness, deposition rate and corrosion resistance of the coating were also evaluated.

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16

Jia, Su Qiu, Jing Xin Guan, Jing Dong Qiu, Hua Chen, and Shu Yan Jia. "Electroless Ni-P Plating on Mg-7Al Alloy by Chemical Conversion Pretreatment." Advanced Materials Research 652-654 (January 2013): 1908–11. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.1908.

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Electroless Ni-P plating on Mg-7Al alloy by chemical conversion pretreatment was investigated. Morphology of electroless nickel plating coatings and phase compositions were measured by SEM, EDX and XRD. The optimized bath composition parameters were determined through orthogonal design. The morphology of electroless nickel plating coatings on Mg-7Al alloy exhibits a nodular structure and resembles the surface of a cauliﬂower and the coating is compact and consists of amorphous Ni-P coating. Potentiodynamic polarization curves of the Ni-P coatings in 3.5% NaCl show that the Ni-P coating extensively improves the corrosion resistance of Mg-7Al alloy and the highest corrosion potential reached to -0.54V vs. SCE(saturated calomel electrode). The results of the orthogonal experiment show that Nickel Sulfate of 25 g/L, Sodium Hypopho-sphate of 25 g/L and Citrate 7.5 g/L can be considered as the optimum bath content parameters for electroless Ni–P plating on Mg-7Al alloy and Nickel Sulfate has more effect on corrosion potential than Sodium Hypophosphate and Citrate..

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17

Venkatakrishnan, P. G., S. S. Mohamed Nazirudeen, and T. S. N. Sankara Narayanan. "Formation and Structural Characterization of Electroless Ni-B-P Ternary Alloy Coatings." Applied Mechanics and Materials 592-594 (July 2014): 385–90. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.385.

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The aim of the present investigation is to study the formation of electroless Ni-B-P alloy coatings and structural and morphological characterization of various coatings with different boron and phosphorous content. An alkaline plating bath with nickel chloride hexahydrate as the source of nickel ions and sodium borohydride and sodium hypophosphite as reducing agents were used for the formation of electroless Ni-B-P alloy coatings. The influence of changes in the concentrations of the reducing agents in the electroless plating bath on the chemical composition, structural and morphological characteristics of the coatings were studied. Scanning electron microscopic studies revealed that the surface morphology of Ni-B-P alloy coatings changed from corn cob-like structure to cauliflower-like structure with increasing borohydride concentration in electroless plating bath, whereas increase in hypophosphite concentration favoured sideway growth, thereby decreased the surface roughness of the Ni-B-P alloy coatings. The peak broadening in the X-Ray Diffraction profiles indicates the large reduction in the crystallite size of the electroless Ni-B-P alloy coatings with increasing boron content in the coating (i.e. for higher borohydride concentration in the plating bath).

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18

Bikulčius, Gedvidas, Sigitas Jankauskas, Aušra Selskienė, Laurynas Staišiūnas, Tadas Matijošius, and Svajus Joseph Asadauskas. "New Insight into Adherence of Ni-P Electroless Deposited Coatings on AA6061 Alloy through Al2O3 Ceramic." Coatings 12, no. 5 (April 26, 2022): 594. http://dx.doi.org/10.3390/coatings12050594.

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The adhesion quality of Ni-P coatings on aluminum is important for mechanical and anticorrosion properties. In this study, the adhesion of Ni-P coatings on nanoporous Al2O3 ceramic (NAC) was evaluated by impact testing. NAC was fabricated on AA6061 alloy by anodizing in sulfuric acid. The deposition of Ni-P coating was carried out on NAC with and without zincate pretreatment. It was found that zincate activation of Al2O3 accelerates the formation of Ni-P coating. A cross-sectional analysis using energy-dispersive X-ray spectroscopy showed that the mechanical properties and impact resistance of the Ni-P coating are strongly related to the chemical composition in the vicinity of its interface with Al2O3. The course of the formation process of Ni-P coating and its mechanisms are also very important. Although the formation of Ni-P coating was slower without zincate treatment, its stronger adhesion to NAC led to superior impact resistance compared to zincate-treated Al2O3. Improved durability of items with Ni-P coatings can benefit many applications.

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19

Yang, Dong, Xin Xin Lin, Huan Ming Chen, Ya Hong Gao, Qiong Lv, and Yan Qing Wang. "Investigation on Properties of Electroless Ni-P-W/Al₂O₃ Composite Coatings Deposited on Sintered NdFeB Permanent Magnet." Advanced Materials Research 476-478 (February 2012): 397–401. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.397.

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The Ni-P-W/Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases linearly with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W amorphous alloy coating, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the amorphous alloy coating obviously. However, for the corrosion resistance of Ni-P-W/Al2O3composite coatings with different Al2O3concentration, there is not a linear increase with the Al2O3concentration increasing. The self-corrosion potential of Ni-P-W/Al2O3composite coatings reaches the highest value while increasing incorporation of Al2O3ratio up to 10 g/L.

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20

Luo, Chuansheng. "Electrochemical corrosion behavior of Ni-P, AlCrN and Ni-P-AlCrN multilayer composite coatings used on grounding grids." Advances in Engineering Technology Research 1, no. 1 (May 18, 2022): 11. http://dx.doi.org/10.56028/aetr.1.1.11.

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In this work, single NiP alloy, we use cathodic arc ion plating and electroless plating, AlCrN and NiP-AlCrN multilayer composite coatings were sedimented from the teeth outwards Q235 carbon steel. It is surface appearances of the coating that were inspected by using scanning electron microscope method (SEM) and the crystal structure, which was researched by the diffraction of X-ray (XRD). The electrochemical corrosion behaviors were evaluated by electrochemical polarization tests with electrochemical impedance spectrum (EIS). The results of EIS displayed that the impedance increased in the order Q235＜AlCrN coating＜NiP alloy＜NiP-AlCrN composite coating. The corroded surfaces of coated samples were covered by some pitting while the surface of Q235 was totally destroyed.

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21

Jia, Su Qiu, Jing Xin Guan, Zhan Kui Zhao, Hua Chen, and Shu Yan Jia. "Optimization of Process Parameters for Electroless Ni-P Plating on AZ91D Magnesium Alloy by Phosphate Pretreatment." Advanced Materials Research 418-420 (December 2011): 808–11. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.808.

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Electroless nickel plating coatings on AZ91D alloy by phosphate pretreatment were prepared. The coating resembles a cauliﬂower and is compact. It consists of amorphous Ni-P. Potentiodynamic polarization curves of the Ni-P coatings in 3.5% NaCl show that the electroless Ni-P coating improves the corrosion resistance of AZ91D alloy and the highest corrosion potential reached to -0.513V vs. SCE. The results of the orthogonal experiment of process parameters indicates that temperature 80°C, time 120min and pH 7.5 can be considered as the optimum process parameters for electroless Ni–P plating on AZ91D alloy and pH value in the bath has more effect on corrosion potential than temperature and time.

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22

Chen, Huan Ming, Ya Hong Gao, Qiong Lv, Dong Yang, and Xin Xin Lin. "Synthesis and Properties of Electroless Ni-P-W/Nano-Al₂O₃ Composite Coatings Deposited on Sintered NdFeB Permanent Magnet." Advanced Materials Research 306-307 (August 2011): 901–6. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.901.

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The Ni-P-W/nano-Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/nano-Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W alloy coatings, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the alloy coating obviously.

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23

Tajbakhsh, Morteza, Omid Yaghobizadeh, and Mahmood Farhadi Nia. "Investigation of the physical and mechanical properties of Ni–P and Ni–P–PTFE nanocomposite coatings deposited on aluminum alloy 7023." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 233, no. 1 (November 24, 2017): 94–103. http://dx.doi.org/10.1177/0954408917744159.

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In this study, various properties of Ni–P and Ni–P–PTFE coating fabricated by electroless process were investigated. These coatings were applied on aircraft-grade aluminum samples. The results showed that the addition of nano-PTFE particles decreases coating rate from 7.1 µm/h to 6.1 µm/h and hardness from 510 HV to 200 HV. Also by increasing the pH value, coating rate increases from 1 µm/h to 7 µm/h. Increasing the solution temperature from 75 ℃ to 90 ℃ also increases the hardness of coating from 125 HV to 210 HV. The results showed that the heat treatment at 300 ℃ for 4 h increases the hardness up to 375 HV due to formation of Ni3P hard phase in Ni–P–PTFE coating. Addition of PTFE particles have improved tribological properties due to its lubricating effects and simultaneously, have reduced corrosion resistance compared to Ni–P coatings, so that the corrosion current for Al, Ni–P, and Ni–P–PTFE coatings is −880, −550, and −770 μA/cm2, respectively.

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24

Ge, Xiao Lan, Bing Zeng, Zhi Chao Chen, Duo Wei, and Cai Jun Wang. "A Study on the Ni-P-SiC Coating of AZ91D Magnesium Alloy." Applied Mechanics and Materials 43 (December 2010): 510–13. http://dx.doi.org/10.4028/www.scientific.net/amm.43.510.

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Анотація:

An Investigation on the Ni-P-SiCp Electroless Composite Plating of AZ91D magnesium alloy was investigated.The morphology and phase structrue of the electroless composite plating were investigated by means of SEM and XRD.The effect of concentration of the second phase particle in electroless plating solution on wear resistance of the Ni-P-SiCp composite coating were studied.The properties of the coatings before and after heat treatment were compared.The result shows that the obtained coatings were flat and compact.X-ray diffractometry indicated that the coatings were amorphous,but crystallization would happen in the process of heat treatment.From the lost weight of the coatings it can be seen that the wear resistance of composite coatings was better than that of Ni-P coatings .

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25

Hsu, Hsien Ta, and Tsong Jen Yang. "Improvement of Adhesion Strength of Electroless Nickel Coating on AZ91D by Anodized Oxide Interlayer." Advanced Materials Research 509 (April 2012): 90–95. http://dx.doi.org/10.4028/www.scientific.net/amr.509.90.

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Анотація:

Nickel-oxide duplex coatings were successfully deposited on magnesium alloy (AZ91D) by anodizing and electroless nickel-phosphorus plating processes. The anodizing interlayer was used to increase the adhesion strength of Ni-P layer. The electroless Ni-P coating enhances the corrosion resistance of the anodic oxide layer. Specimen of AZ91D magnesium alloy was polished firstly. The anodizing process was preceded in alkaline anodizing solution at 24 °C, and the bath voltage maintained at 70 volts for 2 hours. Successive electroless Ni-P plating was used to achieve the sandwich structure. The surface morphologies of the coatings were observed by field-emission scanning electron microscopy (FE-SEM). The adhesion strength was measured by pull-off tester. The electrochemical behavior of coatings with corrosion resistance in 3.5 wt.% NaCl solution was evaluated by potential polarization curve. The experimental results showed that the adhesion strength of directly deposited coating and duplex coating were 115.4 kgf/cm2 and 142.2 kgf/cm2, respectively. The adhesion strength of coatings on AZ91D magnesium alloy was improved by the synergistic effect between anodized magnesium oxide and Ni-P layer in duplex coating.

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26

Sun, Hua, Hong Fang Ma, Li Ming Feng, and Xiao Fei Guo. "Phase Structure and Thermodynamic Stability of Various Nickel-Base Multicomponent Alloy Coating." Applied Mechanics and Materials 457-458 (October 2013): 252–56. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.252.

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Nickel base multi-component alloy Ni-PNi-Cu-PNi-W-P and Ni-Co-P were prepared using electroless plating methodand examined by scanning electronic microscope, x-ray diffractometer and x-ray flourometer respectively on its morphology, component and structure characteristic. Thermodynamic stability of the three samples were also examined by thermal analysis method. Research revealed all three coatings possessed compact and tight surface structure with excellent thermodynamic stability. Also, it was more efficient to enhance the thermodynamic stability of the Ni-P alloy coating by adding atom Cu rather than atom Co or atom W. While Ni-W-P coating demonstrated a microcrystalline structure, both Ni-Co-P and Ni-Cu-P were amorphously structured. After thermal treatment three alloy coatings all experienced transformation from non-crystalline or microcrystalline state to a more stable crystalline state, XDR analysis indicated the reaction products were unit cells and inter metallic compounds of Ni3P.

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27

Wang, Ying, Wan Chang Sun, Hui Cai, Qing Hao Yang, and Ju Mei Zhang. "Preparation and Tribological Behavior of Ni-P-B₄C Electroless Coatings." Materials Science Forum 809-810 (December 2014): 615–20. http://dx.doi.org/10.4028/www.scientific.net/msf.809-810.615.

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In this research, micro-hardness and wear resistance of two types of electroless coatings were investigated including Ni-P and Ni-P-B4C composite coatings. Dispersible B4C particles and electroless Ni-P alloy were codeposited on carbon steel by electroless plating and then heat treated at 200, 400 and 600 °C for 1 h, respectively. The cross-section morphology and microstructure of the composite coatings were characterized. Meanwhile, the micro-hardness and tribological behavior of composite coatings were evaluated. The results showed that the Ni-P-B4C composite coating presents better wear resistance in comparison with that of Ni-P coating. The Ni-P-B4C composite coating with heat treated at 400 °C exhibits high micro-hardness and good wear resistance, which the highest hardness is 1200 HV, the minimum wear weight loss is 0.12 mg and the lowest friction coefficient is 0.2054.

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28

Selvi, V. Ezhil, Purba Chatterji, S. Subramanian, and J. N. Balaraju. "Autocatalytic duplex Ni–P/Ni–W–P coatings on AZ31B magnesium alloy." Surface and Coatings Technology 240 (February 2014): 103–9. http://dx.doi.org/10.1016/j.surfcoat.2013.12.022.

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29

Li, Li, Xiang Cheng, and Feng Shi Yin. "Study on Ultrasonic Electroforming Ni-P Coatings on NdFeB Permanent Magnet." Advanced Materials Research 535-537 (June 2012): 1275–78. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.1275.

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Анотація:

In order to improve the corrosion resistance of sintered NdFeB magnet, experiments are done by the new process which involves ultrasonic electroforming Ni–P alloys. The influence of ultrasonic on electroforming Ni–P alloy on NdFeB was studied by using microscope, adhesion test and NaCl solution immersion test.The results showed that the Ni–P alloy deposit on NdFeB is rough and has poor adhesion without ultrasonic agitation; However, the Ni–P alloy deposit on NdFeB with ultrasonic agitation has the following advantages: uniform and smooth deposit grains, strong adhesion and good corrosion resistance.

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30

Popczyk, Magdalena, and Jolanta Niedbała. "Characterization of corrosion resistance of Zn-Ni-W and Zn-Ni-P-W heat-treated coatings." Inżynieria Powierzchni 25, no. 3-4 (February 17, 2021): 13–17. http://dx.doi.org/10.5604/01.3001.0014.6999.

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The paper presents results of research concerning the evaluation of corrosion resistance of heat-treated alloy coatings (Zn-Ni-W/320°C and Zn-Ni-P-W/320°C). The surface morphology and phase composition of the obtained coatings were determined. Electrochemical corrosion resistance was studied in 5% NaCl solution. On the basis of these studies it was found that the corrosion resistance of Zn-Ni-P-W/320°C coating is higher than Zn-Ni-W/320°C coating.

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31

Popczyk, Magdalena, B. Łosiewicz, Eugeniusz Łągiewka, and A. Budniok. "Electrodeposition and Thermal Treatment of Nickel Coatings Containing Cobalt." Solid State Phenomena 228 (March 2015): 158–62. http://dx.doi.org/10.4028/www.scientific.net/ssp.228.158.

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Анотація:

The Ni-P and Ni-Co-P coatings were electrodeposited at the deposition current density ofjdep= -20 mA cm-2. Thermal treatment of these coatings was conducted in air at 400oC for 1 h. Scanning electron microscopy (SEM) was used for surface morphology characterization of the coatings. Phase composition was investigated by X-ray diffraction (XRD) method. Atomic absorption spectrometry (AAS) was applied to specify chemical composition of obtained coatings. It was found that introduction of Co into amorphous Ni matrix caused the surface development of the obtained deposit. The Ni-P coating revealed an amorphous structure. The Ni-Co-P coating was formed of the amorphous matrix and the amorphous alloy ingredient. Thermal treatment of the coatings allowed to obtain new multi-phase materials with slightly developed surface.

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32

Ramakrishnan, Bijoy, K. Uday Venkat Kiran, Pranit Rangari, Anuj Prajapati, Zuveria Firdouz, Tathwika Jugunta, B. Uday Kumar, Ajeet Srivastav, B. Ratna Sunil, and Ravikumar Dumpala. "Tribological and Morphological Evaluation of Ni-P and Ni-P/D Coatings." Materials Science Forum 969 (August 2019): 73–79. http://dx.doi.org/10.4028/www.scientific.net/msf.969.73.

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The tribological characteristics of Electroless Ni-P and Ni-P/D (diamond) coatings were studied and analysed against AISI 52100 steel ball under dry reciprocating sliding conditions. Low and High Phosphorus Ni-P alloy coatings were deposited on steel substrate by Electroless deposition technique. Diamond particles were successfully reinforced into Ni-P matrix to produce Ni-P/D composite coatings. All coatings were subjected to heat treatment at 400°. The micro-hardness, surface features and elemental composition of the coatings was analysed. The surface morphology of Ni-P and Ni-P/D coatings is detailed. Presence of dia mond particles in Ni-P matrix was confirmed by EDS analysis. Dry sliding wear tests showed a significant enhancement in wear resistance of Ni-P/D composite coatings compared to Ni-P coatings. Experimental results indicate that combined effect of diamond particles reinforcement and heat treatment play a crucial role in modifying the surface characteristics and tribological performance of the Ni-P coatings.

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33

Huang, Chuan Yong. "Electroless Ni-La-P Coatings on 2024 Aluminum Alloys for Aircraft Structure." Applied Mechanics and Materials 224 (November 2012): 348–51. http://dx.doi.org/10.4028/www.scientific.net/amm.224.348.

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2024 aluminium alloys are widely used in airframe construction.However,this series of alloys are susceptible to corrosion to limit their usefulness,In this study,electroless Ni-La-P alloy plating on aluminum alloy and the effects of pH value,temperature and concentration of LaNiO3 on deposition rate were investigated.Surface morphology and corosion-resistant of the electroless Ni-La-P deposits were evaluated.The results showed the corrosion-resistant in 5％ NaC1 solutions obviously enhance compared with original aluminum alloy using electroless Ni-La-P deposition method．

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34

Li, Zhijie, Fei Ma, Dongshan Li, Shanhong Wan, Gewen Yi, Guofang Geng, and Lingyan Guo. "Enhanced Mechanical and Tribological Capabilities of a Silicon Aluminum Alloy with an Electroplated Ni–Co–P/Si3N4 Composite Coating." Metals 12, no. 1 (January 7, 2022): 120. http://dx.doi.org/10.3390/met12010120.

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Ni–Co–P/Si3N4 composite coatings were fabricated over an aluminum–silicon (Al–Si) substrate using a pulse-current electroplating process, in which the rapid deposition of an intermediate nickel–cobalt layer was used to improve coating adhesion. The microstructure, mechanical, and tribological behaviors of the electroplated Ni–Co–P/Si3N4 composite coating were characterized and evaluated. The results revealed that the electroplated Ni–Co–P/Si3N4 composite coating primarily consisted of highly crystalline Ni–Co sosoloid and P, and a volumetric concentration of 7.65% Si3N4. The electroplated Ni–Co–P/Si3N4 composite coating exhibited hardness values almost two times higher than the uncoated Al–Si substrate, which was comparable to hard chrome coatings. Under lubricated and dry sliding conditions, the electroplated Ni–Co–P/Si3N4 composite coating showed excellent anti-wear performance. Whether dry or lubricated with PAO and engine oil, the composite coating showed minimum abrasive wear compared to the severe adhesive wear and abrasive wear observed in the Al–Si substrate.

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35

KOROLYANCHUK, D. G., and V. I. OVCHARENKO. "STRUCTURE AND PHYSICAL-MECHANICAL PROPERTIES OF ELECTROCRYSTALLISED COATINGS OF Ni−P ALLOY." Physical Metallurgy and Heat Treatment of Metals 4, no. 4 (December 28, 2022): 40–46. http://dx.doi.org/10.30838/j.pmhtm.2413.271222.40.909.

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The purpose of the research. Ni−P electrolytic alloy coated products are of great interest in many industries such as electronics (magnetic recording devices), oil and gas industry, medical equipment manufacturing, catalyst manufacturing. In this connection, the task of determining rational deposition modes of electrocrystallized coatings based on Ni−P alloy with increased technological and operational properties and researching their structure arises. In addition, there is a need to replace chrome electrocoatings, which, along with very high indicators of mechanical, protective and decorative properties, are obtained from toxic electrolytes that are dangerous of human life and health. Materials and methodology. In this work, electroplating of Ni−P alloy, obtained from a new electrolyte developed by us, was proposed as a replacement for chromium. Modes of obtaining high-quality electrocoating with Ni−P alloy have been identified, in which the best deposition characteristics, mechanical and decorative properties have been determined. Results. The effect of electrolysis parameters on current output, deposition rate, microhardness, surface morphology and reflectivity of electrocrystallized coatings was investigated. It was also found that the addition of phosphorus ions to the nickel plating electrolyte leads to amorphization of Ni−P alloy deposits. Scientific novelty. The influence of the deposition regime on the formation of the internal structure and surface morphology of Ni−P electrolytic coatings obtained from the electrolyte developed by the authors was studied. Conclusions. The patterns of electrodeposition of Ni−P alloy coatings were studied, and the factors influencing the formation of structure and properties were identified. It was established that the addition of phosphorus ions to the nickel plating electrolyte leads to amorphization of coatings, an increase in microhardness and reflectivity. On the basis of the analysis of the received data, the optimal conditions of electrocrystallization, under which it is possible to obtain a coating with specified physical and mechanical properties, are determined.

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36

Wang, Chun Yu, Gao Hui Wu, Peng Chao Kang, Yun He Zhang, Zi Yang Xiu, and Guo Qin Chen. "The Improvement of Corrosion Resistant for the Cf/Al Composites by Ni-P Coatings." Key Engineering Materials 353-358 (September 2007): 1675–78. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1675.

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Improved corrosion resistance of carbon fiber reinforced aluminum (Cf/Al) matrix composites can be achieved by applying appropriate coatings, and the electroless plating nickel-phosphor (Ni-P) coatings on the Cf/Al composites was provided in this paper. It has been founded that the pretreatment with zinc dipping solution for the electroless plating Ni-P can be approved perfect coatings on the Cf/Al composites. The EDS lines scanning results that the length of Ni-P coating is about 12 +m. In zinc dipping bath, matrix Al alloy surface could catch hold of action points for depositing Ni-P with substitution reaction, however, carbon fibers surface only have adsorption action points from zinc dipping bath, then, Ni-P alloys could deposit on the Al surface or carbon fibers. The uncoated and coated composites samples immersed in 3.5 wt % NaCl solution to contrast. The pitting corrosion behavior of the uncoated composites destroyed materials, therefore, the coated sample appeared pitting only on the surface. The corrosion resistance mechanisms of Ni-P coatings came from inhabiting the formation of the classical galvanic corrosion, additionally, the Ni-P coating was amorphous structure, there was not grains boundary which is sensitive for the corrosion reaction, so the corrosion resistant of Cf/Al composites were improved.

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37

Lelevic, Aleksandra, and Frank C. Walsh. "Electrodeposition of Ni P alloy coatings: A review." Surface and Coatings Technology 369 (July 2019): 198–220. http://dx.doi.org/10.1016/j.surfcoat.2019.03.055.

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38

Chang, Yun Feng, Kung Hsu Hou, and Ming Der Ger. "Multi-Layer Coating for Optical Mold of Strengthening by Electroplating Ni-W and Electroless Plating Ni-Mo-P by Nonisothermal Method." Materials Science Forum 654-656 (June 2010): 1896–99. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1896.

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The development of optical mold coatings has become a key technology in precision optical components in recent years. Researchers are still seeking ideal electroforming materials capable of resisting higher temperature and improve the lifespan of optical mold. Examples of these materials include Ni-W, and Ni-Mo-P alloy plating, among others. However, the literature rarely mentions these alloys as protective coatings. This may be because coating stability, flatness, and strength cannot achieve the desired protective effects. This study develops a combination of two wet electrochemical processes to form a multi-layer coating on optical molds. This coating consists of Ni-W, and Ni-Mo-P alloys. The proposed treatment process attempts to enhance the mechanical strength of the mold and extend its lifespan. We first used electro-deposition to form a thick-film Ni-W coating, and then applied the electroless plating by nonisothermal deposition method (NITD) to create a Ni-Mo-P thin-film and form a multi-layer coating. We also measured the composition, hardness, and elastic modulus of the protective coating as a reference basis for the development of optical molds. The results of this study reveal the appropriate process parameters to provide the multilayer films with a high strength and flat surface. This article can serve as a reference for the development of optical mold coatings.

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39

Su, Yu-Ming, Chia-Che Wu, and Fan-Bean Wu. "Process Heating and Postannealing Effects on Microstructure and Hardness of the Sputtered Ni-P-Al Coatings." Journal of Metallurgy 2011 (January 20, 2011): 1–6. http://dx.doi.org/10.1155/2011/802093.

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Ternary Ni-P-Al alloy coating was fabricated by magnetron sputtering technique with a Ni-P/Al composite target source. The effects of thermal treatments, including deposition process heating and postannealing, on phase transformation phenomenon and related mechanical properties were investigated. The as-deposited coatings produced under process temperature below showed an amorphous/nanocrystalline microstructure. Significant crystallization of Ni matrix and precipitation of and compounds were observed for the coatings manufactured under high sputtering temperatures above . The amorphous Ni-P-Al coatings were postannealed from 500 to in vacuum environment for comparison. The amorphous feature of the Ni-P-Al coating remained unchanged under a high annealing temperature of , showing a superior thermal stability as compared to those fabricated under high process temperatures. Superior hardness was obtained for the post-annealed Ni-P-Al coatings due to volumetric constraint of crystallization and precipitation. On the other hand, the overaging phenomenon and subsequent degradation in hardness were found for the Ni-P-Al coatings fabricated under high-temperature deposition processes. The phase transformation mechanisms of the coatings through different thermal treatments were intensively discussed.

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40

Sun, Hua, Hong Fang Ma, Li Ming Feng, and Xiao Fei Guo. "Effect of Ce Co-Deposition on Phase Structure and Thermal Stability of Ni-Cu-P Alloy." Applied Mechanics and Materials 457-458 (October 2013): 248–51. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.248.

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Two nickel base multicomponent Ni-Cu-P, Ni-Cu-P-Ce alloy coatings were prepared using electroless plating method in low acidity condition, and examined by scanning electronic microscope, x-ray diffractometer and x-ray flourometer respectively on its morphology, component and structure characteristic. Thermodynamic stability of the two samples were also examined by thermal analysis method. Research revealed a microcrystalline characteristic with compact and tight surficial cellular structure of Ni-Cu-P-Ce coating. And addition of Cu and Ce into Ni-P alloy could enhance thermodynamic stability of the coating, and let coatings transformation temperature from amorphous state to crystalline state increase approximately to 480°C Celsius. X-ray diffraction analysis indicated the reaction products to be crystal grains of nickel atoms and intermetallic compound of Ni3P.

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41

Qin, Xiu Lan, Lin Jie He, Yan Li Wang, Ke Wang, Ming Ming Gao, Yang Zhang, Xin Ke Yang, Qian Chen, Wei Hua Dong, and Lu Zhang. "The Preparation and Research of the Electroless Plating Rare Earth Alloys." Advanced Materials Research 1052 (October 2014): 101–8. http://dx.doi.org/10.4028/www.scientific.net/amr.1052.101.

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The Ni-Fe-La-P rare earth alloys of glass fiber were prepared. Rare earth element lanthanum (La) was first introduced into glass fiber by electroless plating, in order to improve and adjust the chemical, physical properties and microstructure of alloy coatings. The application of rare earth element La in electroless plating was explored. The results showed that an appropriate amount of rare earth element La could improve the stability of the chemical plating solution and reduce the temperature of electroless plating by 6 °C ~ 20 °C. The rare earth element La not only could make the morphology of alloy coatings compacted, smooth and uniform, but also could greatly improve the contents of Fe, Ni and could tremendously reduce the content of P in the alloy coatings of glass fiber. The conductivity and magnetic properties of the alloy coatings could be increased by rare earth element La. In the preparation of the Ni-Fe-La-P electroless alloys of glass fiber, the optimal content of La2O3 was 1.2 g·L-1. Rare earth element La could promote the transition of alloy coatings from amorphous state to rystal state, improve the electromagnetic performances of alloy coatings and enhance the electromagnetic wave absorbing properties of alloy coatings.

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42

Yu, Zu Xiao, Ya Li Sun, and Xin Huang. "The Influences of Additives on the Corrosion Resistant Properties of Electroless Plating Ni-Co-P Alloy on the AZ91D Magnesium Alloy." Advanced Materials Research 1004-1005 (August 2014): 733–36. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.733.

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Анотація:

To improve the anti-corrosion properties of the AZ91D magnesium alloy, the electroless plating Ni-Co-P on the AZ91D magnesium alloy is necessary. The influences of additives (ammonium fluoride (NH4F) and hexamethylenetetramine (HMTA)) on deposition rate, corrosion rate, acid resistance, corrosion current, corrosion potential and webster hardness of electroless plating Ni-Co-P alloy coating, were investigated using electrochemical methods, etc. The results show that the deposition rate and corrosion resistance properties of electroless plating Ni-Co-P are obviously improved when the additives, including NH4F (2%) and hexamethylenetetramine (HMTA, 1%), are added into plating solution, respectively. In addition, the global particles in the Ni-Co-P coating become smaller with the addition of NH4F by comparison with no additives and coatings are dense, uniform and defect-free.

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43

Buchtík, Martin, Michaela Krystýnová, Jiří Másilko, and Jaromír Wasserbauer. "The Effect of Heat Treatment on Properties of Ni–P Coatings Deposited on a AZ91 Magnesium Alloy." Coatings 9, no. 7 (July 23, 2019): 461. http://dx.doi.org/10.3390/coatings9070461.

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The present study reports the effect of phosphorus content in deposited electroless nickel (Ni–P) coatings, the heat treatment on the microhardness and its microstructural characteristics, and the influence of the temperature on the microstructure of the Mg alloy substrate during the heat treatment. The deposition of Ni–P coatings was carried out in the electroless nickel bath, and the resulting P content ranged from 5.2 to 10.8 wt.%. Prepared samples were heat-treated in the muffle furnace at 400 °C for 1 h after the coating deposition. The cooling of the samples to room temperature was proceeded in the air. For as-deposited and heat-treated samples, it was determined that with the increasing P content, the microhardness was decreasing. This may be caused by the changes in the structure of the Ni–P coating. The X-ray diffraction patterns of the as-deposited Ni–P coatings showed that the microstructure changed their nature from crystalline to amorphous with the increasing P content. The heat treatment of prepared samples led to the significant increase of microhardness of Ni–P coatings. All the heat-treated samples showed the crystalline character, regardless of the P content and the presence of hard Ni3P phase, which can have a positive effect on the increase of microhardness. The metallographic analysis showed changes of substrate microstructure after the heat treatment. The prepared coatings were uniform and with no visible defects.

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44

Wang, Fei Fei, and Li Li. "Investigation of Ultrasonic Electroplating Ni-P Coatings on Nd-Fe-B Permanent Magnet." Advanced Materials Research 284-286 (July 2011): 980–83. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.980.

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In order to improve the corrosion resistance of Nd-Fe-B, the new technological process is done which involves electroplating Ni–P alloys with ultrasonic. The influence of ultrasonic on electroplating Ni–P alloy on Nd-Fe-B was studied by using microscope, adhesion test and NaCl solution immersion test. The results showed that the Ni–P alloy deposit on Nd-Fe-B is rough and has poor adhesion without ultrasonic agitation; however, the Ni–P alloy deposit on Nd-Fe-B with ultrasonic agitation has more compact and uniform microstructure, smoother morphology. At the same time, the adhesion and corrosion resistance are greatly enhanced.

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45

Xian, Jieyu, Zhenyu Shen, Zhengwei Zhang, Hongbin Wu, Meifu Jin, and Minjie Jiang. "Effect of Current Density on the Wear Resistance of Ni–P Alloy Coating Prepared through Immersion-Assisted Jet-Electrodeposition." Coatings 11, no. 5 (April 29, 2021): 527. http://dx.doi.org/10.3390/coatings11050527.

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Анотація:

To improve the wear resistance of 45 steel surfaces, a Ni−P alloy coating was prepared on the surface of 45 steel with an immersion-assisted jet-electrodeposition technology. Scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction and confocal microscopy were used in testing the surface morphology, composition, structure, grain size, and wear scar parameters of the coating. The effect of immersion-assisted jet-electrodeposition on the wear resistance of Ni−P alloy coating at current densities of 20–60 A·cm−2 were explored and analyzed. Results showed that the surface quality, microhardness, and wear resistance of Ni−P alloy coatings prepared through immersion-assisted jet-electrodeposition were improved compared with those of the coatings prepared through traditional jet-electrodeposition. With the increase in the current density, the surface cell structure of the alloy coating was refined, the flatness was improved, the surface Ni content was increased, the grain size was refined, and the coating thickness, the microhardness, and wear resistance showed a trend of first increasing and then decreasing. The best surface quality of the coating was observed at a current density of 50 A·cm−2. Moreover, the unit cell structure was obvious, the surface was flat and dense, the coating thickness was the largest, reaching 21.42 μm, the highest Ni content was obtained (98.25 wt.%), the smallest grain size (6.6 nm) was obtained, the microhardness of the coating reached a maximum value (725.58 HV0.1), and the best wear resistance was observed.

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46

Agarwala, Ramesh Chandra. "Studies on Electroless Coatings." Defect and Diffusion Forum 237-240 (April 2005): 952–57. http://dx.doi.org/10.4028/www.scientific.net/ddf.237-240.952.

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Since the introduction of Electroless (EL) coating in 1946 by Brenner and Riddle, the process has been the subject of steady growth. It is one of the most elegant methods available for the production of protective coatings on surface. The technique involves the autocatalytic reduction, at the substrate/solution interface, of cations released from suitable chemical reducing agents with in the EL bath. EL coating technique is simple one, as can be manifested just by controlling pH and temperature of the coating bath. Such coatings are reported to provide excellent physical and mechanical properties. The nickel, silver and copper based alloy and composite EL coatings are being studied at Indian Institute of Technology Roorkee since 1985 and this paper deals with the gist of the same. The structural behavior of Ni-P coatings for different phosphorus contents has been extensively studied. Transmission electron microscopy (TEM) and magnetic movement studies have been used as tools for structural and kinetic studies, respectively. Submicron size coating islands and their transformations have been deduced. The metallography studies using hot stage within TEM to follow the phase transformations occurring at various temperatures have been studied for Ni-B, EL coatings. As a forward step towards composite coatings, Ni-P-C, Ni-P-Al2O3, Ni-P-ZrO2 etc. have been developed by co-deposition techniques. Ag-graphite composite coatings produced by EL technique exhibits ~5 times higher wear resistance and ~ 2 times better corrosion resistance apart from being a good electrical conductor. The tribological behavior of EL Ni-P-X and Ni-P coatings on steel and aluminium substrates in different conditions i.e., as-coated, heat treated at various temperatures at different extents of time with different normal loads, have been studied in terms of dry sliding friction and wear against counter face of case hardened steel. In Ni-P-X nanocoatings (X= ZrO2-Al2O3-Al3Zr), X has been produced in-situ and are composed of nano-sized particles. Such coating could be produced uniformly on carbon fibre of 7µ diameter. Ni-P and Cu are also coated successfully on graphite/ oxide powders of ~ 120µ sizes. Micro-thickness coatings are paving ways to nanocoatings. These are the coatings in which either the thickness of the coating is in nano level or the second phase, that dispersed in the coating matrix is of nano-size. Ni-P-Ferrite nano coatings with thickness less than ~0.1mm thick, is found to exhibit about 20db of absorption of microwave in the rage of 12-18 GHz which can be exploited for radar applications. Here the nano-sized ferrite particles are co-deposited along with the Ni-P EL coatings.

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47

Wang, Jian Jian, Si Ran Li, Xun Jia Su, Gen Liang Hou, Bi Song, and Chao Hui Liu. "Study on Wear Resistance of Two Types of Low Phosphorus Electroless Nickel Plating on 30CrMnSi." Advanced Materials Research 1142 (January 2017): 178–82. http://dx.doi.org/10.4028/www.scientific.net/amr.1142.178.

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Acid Ni-P and alkaline Ni-P coatings were prepared on 30CrMnSi alloy steel by electroless plating method. 3 pH values were selected for each type. The phosphorus content, hardness and wear resistance coefficient of the 6 kinds of coatings were tested. Experimental results showed that the mass fraction of P was less than 4% range, with the increase of P content, the hardness and wear resistance of two kinds of coating had been improved, the hardness and wear resistance of acid coating were better than that of alkali coating.

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48

Cheng, Yan Hai, Shi Ju Zhang, Yu Xing Peng, Fang Fang Xing, Jie Li, and Zhen Cai Zhu. "SiC Particles Concentration Dependent the Properties of Electroless Ni-P-SiC Coatings." Advanced Materials Research 457-458 (January 2012): 146–49. http://dx.doi.org/10.4028/www.scientific.net/amr.457-458.146.

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In this study, Ni-P-SiC composite coatings were prepared by adding different amount of SiC particles into electroless Ni-P plating solution. The effects of SiC particles concentration in solution on depositing rate and composition of the coatings were investigated. The different SiC contents in coatings could be obtained by adjusting the amount of SiC particle concentration in electroless plating solution. Scanning electron microscopy (SEM) results indicate that SiC particles are dispersed in the composite coating and Ni-P alloy is mainly as a bond metal envelope with SiC particles. At the same time, the microhardness became increased and the wear resistance improved with the increasing of SiC content.

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49

CHEN, Xiao-ming, Guang-yu LI, and Jian-she LIAN. "Deposition of electroless Ni-P/Ni-W-P duplex coatings on AZ91D magnesium alloy." Transactions of Nonferrous Metals Society of China 18 (December 2008): s323—s328. http://dx.doi.org/10.1016/s1003-6326(10)60225-7.

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50

Palaniappa, M., and S. K. Seshadri. "Friction and wear behavior of electroless Ni–P and Ni–W–P alloy coatings." Wear 265, no. 5-6 (August 2008): 735–40. http://dx.doi.org/10.1016/j.wear.2008.01.002.

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