Copper Electroplating Process and Performance of HEDP-potassium Pyrophosphate System on Sintered NdFeB Surface

doi:10.11902/1005.4537.2024.080

Journal of Chinese Society for Corrosion and protection

2025, Vol. 45

Issue (3): 687-697 DOI: 10.11902/1005.4537.2024.080

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Copper Electroplating Process and Performance of HEDP-potassium Pyrophosphate System on Sintered NdFeB Surface

WANG Kang¹^,², JIANG Jianjun², YANG Lijing², SONG Zhenlun²(

)

^1.Faculty of Mechanical Engineering & Mechanics, Ningbo University, Ningbo 315211, China
^2.Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China

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WANG Kang, JIANG Jianjun, YANG Lijing, SONG Zhenlun. Copper Electroplating Process and Performance of HEDP-potassium Pyrophosphate System on Sintered NdFeB Surface. Journal of Chinese Society for Corrosion and protection, 2025, 45(3): 687-697.

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Abstract

The Cu electroplating on sintered NdFeB was conducted with hydroxyethylidene diphosphonic acid (HEDP) as a cyanide-free alkaline plating electrolyte and potassium pyrophosphate as an auxiliary complexing agent. Meanwhile, the plating process was optimized through cyclic voltammetry (CV), cathodic current efficiency, Hall tank experiments, scanning electron microscopy (SEM) and other means; then the plated coatings were characterized by means of SEM and scratch test etc., and their corrosion resistance was assessed by salt spray test. The results showed that the coatings with smooth surface, defect free and good adhesion to the NdFeB substrate may be acquired with an electrolyte composed of CuSO₄·5H₂O 22.5 g·L^-1, HEDP 60 g·L^-1, K₄P₂O₇ 40 g·L^-1 and K₂SO₄ 10 g·L^-1 of pH = 10, at 50 ℃, by stirring rate of 200 r·min^-1, and current density of 0.6 A·dm^-2. The corrosion resistance of the Cu-plating is close to that of conventional Ni-Cu-Ni plating; Besides, the surface magnetic and magnetic flux results show that the magnetic shielding effect of direct Cu plating on NdFeB surface is smaller than that of Ni-Cu-Ni plating.

Key words: electroplated Cu cyanide-free alkaline HEDP cathode current efficiency binding force table magnetic

Received: 13 March 2024 32134.14.1005.4537.2024.080

ZTFLH:

TG174

Fund: National Key Research and Development Program(2021YFB3502900)

Corresponding Authors: SONG Zhenlun, E-mail: songzhenlun@nimte.ac.cn

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https://www.jcscp.org/EN/10.11902/1005.4537.2024.080 OR https://www.jcscp.org/EN/Y2025/V45/I3/687

Table 1 Bath composition and experimental conditions for copper plating

Table 2 Subjects and conditions of single variable experiment

Fig.1 Schematic diagram of appearance of Hull cell specimen after plating

Fig.2 Cyclic voltammetry curves in alkaline Cu plating solutions containing different concentrations of CuSO₄

Fig.3 Titration curves of the baths containing different concentrations of CuSO₄ (a) and solution states during titration (b)

Fig.4 Effects of the contents of CuSO₄ (a), HEDP (b) and potassium pyrophosphate (c) on cathode current efficiency

Fig.5 SEM surface morphologies of the coatings deposited in the baths containing 50 g·L^-1 (a1), 60 g·L^-1 (a2), 70 g·L^-1 (a3), 80 g·L^-1 (a4) HEDP and 10 g·L^-1 (b1), 20 g·L^-1 (b2), 40 g·L^-1 (b3),60 g·L^-1 (b4) potassium pyrophosphate

Fig.6 Standard strips of Hull cell cathode specimen

Fig.7 Visualizations of the surface of Hull cell specimen under different conditions of heating temperature (a) and pH values (b)

Fig.8 SEM surface morphologies of the coatings deposited at different current densities: (a) 0.6 A·dm^-2, (b) 0.9 A·dm^-2, (c) 1.2 A·dm^-2, (d) 1.5 A·dm^-2

Fig.9 Cross-sectional profiles and 3D morphologies of the coatings plated at different current densities: (a) 0.6 A·dm^-2, (b) 0.9 A·dm^-2, (c) 1.2 A·dm^-2, (d) 1.5 A·dm^-2

Fig.10 SEM morphologies of the coatings deposited in the plating solutions containing the auxiliary complexing agents of potassium citrate (a), potassium sodium tartrate (b), TEA (c) and EDTA (d)

Fig.11 Cross-sectional morphologies of the coatings plated in the plating solutions containing the complexing agents of potassium citrate (a) and potassium sodium tartrate (b)

Fig.12 Cross-sectional morphology of pure Cu plating

Fig.13 Scratch tests of Cu plating before (a) and after (b) adhesive tape stripping

Fig.14 Macroscopic morphologies of Cu-Ni (a1-d1), Ni-Cu-Ni (a2-d2), and Cu-Ni-Chemical Ni (a3-d3) plated coatings after NSS tests for 0 h (a1-a3), 24 h (b1-b3), 48 h (c1-c3), and 72 h (d1-d3)

Fig.15 Surface magnetic induction intensities and magnetic fluxes of NdFeB specimens with different plated coatings

[1]	Wang F, Chen X P, Qiu P, et al. Corrosion resistance of electroplating of Cu-Ni/P coatings on NdFeB magnet materials [J]. Int. J. Electrochem. Sci., 2020, 15: 10476
[2]	Sun S, Yang J, Qian X Z, et al. Preparation and electrochemical corrosion behavior of electroless plated Ni-Cr-P alloy coating [J]. J. Chin. Soc. Corros. Prot., 2020, 40: 273
	孙硕, 杨杰, 钱薪竹等. Ni-Cr-P化学镀层的制备与电化学腐蚀行为 [J]. 中国腐蚀与防护学报, 2020, 40: 273
[3]	Yin T T, Wu R Z, Leng Z, et al. The process of electroplating with Cu on the surface of Mg-Li alloy [J]. Surf. Coat.Technol., 2013, 225: 119
[4]	Zheng J W, Chen H B, Qiao L, et al. Double coating protection of Nd-Fe-B magnets: intergranular phosphating treatment and copper plating [J]. J. Magn. Magn. Mater., 2014, 371: 1
[5]	Li M G, Wei G Y, Li M, et al. Effect of HEDP on copper electroplating from non-cyanide alkaline baths [J]. Surf. Eng., 2014, 30: 728
[6]	Zhang J, Liu A M, Ren X F, et al. Electrodeposit copper from alkaline cyanide-free baths containing 5,5′-Dimethylhydantoin and citrate as complexing agents [J]. RSC Adv., 2014, 4: 38012
[7]	Zhang H, Song Y W, Song Z L. Electrodeposited nickel/alumina composite coating on NdFeB permanent magnets [J]. Mater. Corros., 2008, 59: 324
[8]	Ma C B, Cao F H, Zhang Z, et al. Electrodeposition of amorphous Ni-P coatings onto Nd-Fe-B permanent magnet substrates [J]. Appl. Surf. Sci., 2006, 253: 2251
[9]	Ibrahim M A M, Bakdash R S. New non-cyanide acidic copper electroplating bath based on glutamate complexing agent [J]. Surf. Coat. Technol., 2015, 282: 139
[10]	Chen H B, Zheng J W, Fu Y C, et al. Preparation and characterization of copper-graphene composite films on sintered NdFeB surface [J]. Rare. Met. Mater. Eng., 2021, 50: 4306
	陈海波, 郑精武, 付永成等. 烧结NdFeB表面铜-石墨烯复合膜的制备与表征 [J]. 稀有金属材料与工程, 2021, 50: 4306
[11]	Li Y, Zhu L Q, Li W P, et al. Electrodeposition and properties of copper layer on NdFeB device [J]. J. Mater. Eng., 2017, 45(6): 55 doi: 10.11868/j.issn.1001-4381.2015.001426
	李悦, 朱立群, 李卫平等. 钕铁硼器件表面电沉积铜层及性能 [J]. 材料工程, 2017, 45(6): 55
[12]	Fabbri L, Giurlani W, Mencherini G, et al. Optimisation of thiourea concentration in a decorative copper plating acid bath based on methanesulfonic electrolyte [J]. Coatings, 2022, 12: 376
[13]	Zheng J W, Chen H B, Cai W, et al. Reaction mechanisms of copper electrodeposition from 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) solution on glassy carbon [J]. Mater. Sci. Eng., 2017, 224B: 18
[14]	Ramírez C, Bozzini B, Calderón J A. Electrodeposition of copper from triethanolamine as a complexing agent in alkaline solution [J]. Electrochim. Acta., 2022, 425: 140654
[15]	Jiang J, Jiang J J, Yang L J, et al. Preparation and corrosion resistance of Zn-Al coating on sintered NdFeB permanent magnet [J]. J. Chin. Soc. Corros. Prot., 2023, 43: 104
	江杰, 姜建军, 杨丽景等. 烧结NdFeB表面Zn-Al涂层制备及耐腐蚀机理研究 [J]. 中国腐蚀与防护学报, 2023, 43: 104
[16]	Zhuang C, Ling G P. Electrodeposition of copper on NdFeB in CuCl-EMIC ionic liquid [J]. Surf. Technol. 2019, 48: 260
[17]	Chen H M, Wang S X, Zhang Q, et al. Electrodeposition behavior of silver in an alkaline DMH plating bath with 5,5-Dimethylhydantoin as complexing agent [J]. J. Chin. Soc. Corros. Prot., 2023, 43: 896
	陈惠敏, 王帅星, 张骐等. 5,5-二甲基乙内酰脲配位体系中银的电沉积行为研究 [J]. 中国腐蚀与防护学报, 2023, 43: 896 doi: 10.11902/1005.4537.2022.262
[18]	Zheng J W, Wang S Y, Zhang S, et al. A novel self-repairing hydrophobic composite coating for anti-corrosion protection of sintered Nd-Fe-B [J]. J. Mater. Res. Technol., 2023, 22: 3020

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