目的 针对海洋旋转密封装置使用到的碳化硅机械密封环存在的高磨损问题,对表面改性防护涂层的“高硬度-低摩擦-耐磨损”协同性能提出要求。方法 本研究采用热丝化学气相沉积(HFCVD)与磁控溅射辅助离子束沉积复合工艺,设计并制备了金刚石/类金刚石碳(DLC)复合涂层。首先通过HFCVD技术在碳化硅基底表面制备具有不同晶粒尺寸的微晶金刚石(MCD)、超细纳米晶金刚石(UNCD)涂层,随后利用磁控溅射辅助离子束沉积在其表面构筑DLC润滑功能层,形成“刚性底层-润滑表层”的双层结构,旨在协同金刚石的超高硬度与DLC的低摩擦特性,克服单一涂层的性能局限。随后,系统研究复合涂层在模拟海水环境中的摩擦学性能。结果 类金刚石可以改善金刚石涂层的表面形貌,而且通过将二者结合起来可以有效弥补各自的短板,实现协同性能需求,最终使金刚石/类金刚石复合涂层在模拟海水环境中拥有比单一金刚石涂层更优的摩擦性能。结论 DLC的引入使MCD基底粗糙度从155.33 nm降至123.77 nm、UNCD基底的粗糙度从92.43 nm降至81.90 nm,且MCD/DLC的稳态摩擦系数与比磨损率分别降低32.08%、12.22%,UNCD/DLC的分别改善26.67%、20.92%。结合扫描电镜(SEM)、拉曼光谱(Raman)及X射线光电子能谱(XPS)对摩擦前后涂层表面形貌与结构分析,揭示表层的类金刚石碳膜能够有效减弱界面剪切应力,从而增强边界润滑效应,而且DLC的存在加速了摩擦引起的石墨化过程。
Abstract
To address the simultaneous and critical demand of marine moving parts for advanced protective coatings that synergistically combine high hardness, low friction coefficient, and exceptional corrosion resistance, an innovative diamond/DLC duplex coating architecture is strategically designed and fabricated through a hybrid deposition approach integrating hot-filament chemical vapour deposition (HFCVD) and magnetron-sputter-assisted ion-beam deposition. This sophisticated fabrication methodology is specifically conceived to engineer a composite coating system that overcomes the inherent limitations of monolithic coatings. The deposition sequence commences with the synthesis of foundational diamond layers onto silicon carbide (SiC) substrates by HFCVD. Two distinct diamond morphologies are engineered: a micro-crystalline diamond (MCD) layer, characterized by its faceted, large-grain structure providing supreme load-bearing capacity, and an ultra-nanocrystalline diamond (UNCD) layer, featuring exceptionally fine, nanometer-scale grains that yield a naturally smoother surface finish. These diamond layers serve as the primary, rigid mechanical support, and are engineered to resist extreme contact pressures and abrasive wear in harsh marine environments. Subsequently, a uniform, hydrogenated diamond-like carbon (DLC) lubricating topcoat is deposited onto these diamond underlayers via the magnetron-sputter-assisted ion-beam deposition technique, renowned for producing dense, adherent amorphous carbon films with controlled sp3/sp2 bonding ratios. This precise two-stage synthesis successfully yields a functionally graded "rigid underlayer-lubricating top layer" architectural design. The fundamental operational principle of this architecture lies in its ability to synergistically harness the ultrahigh hardness and outstanding chemical inertness intrinsic to the diamond phases, while simultaneously capitalizing on the excellent solid-lubricating properties and low shear strength characteristic of the DLC topcoat, thereby effectively overcoming the performance compromises typically encountered in single-layer coating systems, such as the high initial roughness of MCD or the limited mechanical support of standalone DLC films. Comprehensive tribological characterization is systematically performed in a simulated seawater environment to evaluate the coating performance under conditions relevant to marine applications. Surface profilometry measurements quantitatively demonstrate the critical role of the DLC overlayer in surface engineering, showing that it significantly reduces the arithmetic mean surface roughness (Ra) of the underlying MCD base layer from an initial 155.33 nm to a final 123.77 nm, thereby mitigating the initial abrasive interactions and potential stress concentration. A corresponding, though less pronounced, smoothing effect is observed on the inherently finer UNCD base layer, where the Ra parameter is further diminished from 92.43 nm to 81.90 nm following the conformal DLC deposition. Ball-on-disk tribometer testing under controlled conditions provides quantitative evidence of substantial performance enhancement for the duplex coatings relative to their uncoated diamond counterparts. Specifically, the MCD/DLC hybrid configuration exhibits a remarkable 32.08% reduction in its steady-state friction coefficient and a 12.22% decrease in its calculated specific wear rate. Meanwhile, the UNCD/DLC architecture demonstrates even more impressive friction performance with a 26.67% reduction in the steady-state friction coefficient, coupled with a more substantial 20.92% improvement in wear resistance, highlighting the particular efficacy of combining the DLC topcoat with the naturally smoother UNCD underlayer. Post-test characterization of the worn surfaces utilizing scanning electron microscopy (SEM), micro-Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) provides mechanistic insights into the tribological behavior. These analytical techniques collectively reveal that the DLC film performs multiple critical functions during sliding contact: it effectively alleviates interfacial shear stresses by acting as a compliant, low-shear-strength layer, thereby enhancing boundary lubrication regimes. Furthermore, the metastable nature of the DLC's amorphous carbon network accelerates the kinetics of friction-induced graphitization, facilitating the formation of a sp2-carbon-rich tribofilm that provides easy shear planes at the contact interface. The synergistic interaction between this graphitized tribolayer and the aqueous environment of the simulated seawater, where water molecules act as both cooling agents and passive lubricants, contributes significantly to the observed friction and wear reduction. This research, therefore, provides both a fundamental scientific basis for understanding the tribochemical mechanisms in hierarchical carbon-based coatings in aqueous environments and a practical, scalable engineering route for developing next-generation, long-life protective coatings for critical moving parts in high-end marine equipment, such as propeller shaft bearings, hydraulic piston pumps, and underwater robotic joints, operating under simultaneous mechanical and corrosive challenges.
关键词
金刚石 /
类金刚石 /
复合涂层 /
海水环境 /
摩擦机制
Key words
diamond /
diamond-like carbon (DLC) /
composite coating /
seawater environment /
tribological mechanism
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参考文献
[1] 范舒瑜, 匡同春, 林松盛, 等. WC? Co硬质合金/CVD金刚石涂层刀具研究现状[J]. 材料导报, 2023, 37(8): 24-33.
FAN S Y, KUANG T C, LIN S S, et al.Research Progress on Cutting Tools Made from WC? Co Cemented Carbide Substrates and Coated with CVD Diamond[J]. Materials Reports, 2023, 37(8): 24-33.
[2] 万书宏, 林晶, 冯帅. 热丝CVD法制备金刚石涂层刀具的研究现状[J]. 真空, 2022, 59(1): 40-47.
WAN S H, LIN J, FENG S.Research Progress of Diamond Coated Tools Prepared by Hot Filament CVD[J]. Vacuum, 2022, 59(1): 40-47.
[3] 吴勇, 郭于洋, 孙清云, 等. CVD金刚石薄膜与涂层制备技术及关键领域应用研究进展[J]. 表面技术, 2025, 54(16): 18-38.
WU Y, GUO Y Y, SUN Q Y, et al.Research Progress on Preparation Technologies and Key Field Applications of CVD Diamond Films and Coatings[J]. Surface Technology, 2025, 54(16): 18-38.
[4] 欧正雄, 夏岳, 王凯悦, 等. 金刚石涂层的干摩擦性能及在机械密封应用[J]. 中国表面工程, 2024, 37(6): 257-270.
OU Z X, XIA Y, WANG K Y, et al.Dry-Friction Properties of Diamond Coatings in Mechanical-Seal Applications[J]. China Surface Engineering, 2024, 37(6): 257-270.
[5] OHTAKE N, HIRATSUKA M, KANDA K, et al.Properties and Classification of Diamond-Like Carbon Films[J]. Materials, 2021, 14(2): 315.
[6] 江子厚, 邓阳, 王成勇, 等. 类金刚石刀具涂层研究进展[J]. 工具技术, 2023, 57(11): 3-14.
JIANG Z H, DENG Y, WANG C Y, et al.Research Progress of Diamond-Like Carbon Coating for Cutting Tool[J]. Tool Engineering, 2023, 57(11): 3-14.
[7] 朱圭娜, 魏芳, 许世鹏, 等. 医用护目镜用疏水和亲水涂层的研究进展[J]. 山西化工, 2025, 45(6): 38-40.
ZHU G N, WEI F, XU S P, et al.Research Progress on Hydrophobic and Hydrophilic Coatings for Medical Goggles[J]. Shanxi Chemical Industry, 2025, 45(6): 38-40.
[8] 汪科良, 刑振华, 任守志, 等. 超润滑薄膜研究进展及在航天领域的应用展望[J]. 材料导报, 2025, 39(15): 8-16.
WANG K L, XING Z H, REN S Z, et al.Research Progress on Super-Lubricating Films and Prospect of Its Astronautical Applications[J]. Materials Reports, 2025, 39(15): 8-16.
[9] 李安, 李霞, 王云锋, 等. 厚类金刚石碳基薄膜的制备及摩擦与腐蚀性能的表征[J]. 表面技术, 2019, 48(4): 253-261.
LI A, LI X, WANG Y F, et al.Preparation of Thick Diamond-Like Carbon Based Films and Characterization of Friction and Corrosion Properties[J]. Surface Technology, 2019, 48(4): 253-261.
[10] 武帅政, 张树玲, 黄腾龙, 等. 厚类金刚石膜研究进展[J]. 热加工工艺, 2023, 52(10): 14-19.
WU S Z, ZHANG S L, HUANG T L, et al.Research Progress of Thick Diamond-Like Carbon Coating[J]. Hot Working Technology, 2023, 52(10): 14-19.
[11] 程影春,丁啸云,崔梦辉,等.类金刚石薄膜膜基结合强度调控研究现状[J/OL]. 中国表面工程,1-17[2025-09-24].
CHENG Y C, DING X Y, CUI M H, et al. Review Status of Adhesion Strength Regulation of Diamond-like Carbon Films[J/OL]. China Surface Engineering, 1-17[2025-09-24].
[12] YUAN S, GUO X G, WANG H, et al.Atomistic Understanding of Rough Surface on the Interfacial Friction Behavior during the Chemical Mechanical Polishing Process of Diamond[J]. Friction, 2024, 12(6): 1119-1132.
[13] ZHU H J, LIU D D, LEI X L, et al.Polishability and Tribological Performances of Various CVD Diamond Coatings Deposited on SiC Ceramics Seal Ring[J]. Tribology International, 2025, 212: 110943.
[14] ZENG Q F.Thermally Induced Superlow Friction of DLC Films in Ambient Air[J]. High Temperature Materials and Processes, 2018, 37(8): 725-731.
[15] RONKAINEN H, HOLMBERG K.Environmental and Thermal Effects on the Tribological Performance of DLC Coatings[M]. Boston: Springer US, 2007: 155-200.
[16] LIU X, DING X Q, YUAN Q, et al.Ultralow Friction of MoS2/H-DLC Composite at Elevated Temperature[J]. Diamond and Related Materials, 2025, 157: 112467.
[17] JIA Z, DONG C H, LIN W M, et al.Polyimide/DLC Double-Layered Coatings Achieving Ultralow Friction at Elevated Temperatures[J]. Tribology International, 2026, 213: 111113.
[18] CUI Y X, MA J H, WANG T G, et al.Synergistic Friction-Reducing and Anti-Wear Behaviors of DLC on NCD Films via In-Situ Synthesis by Fs Laser Ablation[J]. Surface and Coatings Technology, 2021, 409: 126947.
[19] RANI R, PANDA K, KUMAR N, et al.Triboenvironment Dependent Chemical Modification of Sliding Interfaces in Ultrananocrystalline Diamond Nanowall Film: Correlation with Friction and Wear[J]. The Journal of Physical Chemistry C, 2018, 122(1): 945-956.
[20] PANICH A M, SHAMES A I, MOGILYANSKY D, et al.Detonation Nanodiamonds Fabricated from Tetryl: Synthesis, NMR, EPR and XRD Study[J]. Diamond and Related Materials, 2020, 108: 107918.
[21] PANDEY M, D’CUNHA R, TYAGI A K. Defects in CVD Diamond: Raman and XRD Studies[J]. Journal of Alloys and Compounds, 2002, 333(1/2): 260-265.
[22] 熊江. 热丝CVD法生长纳米金刚石膜及其生长机理研究[D]. 武汉: 武汉工程大学, 2015.
XIONG J.Study on the Preparation and Growth Mechanism of Nanocrystalline Diamond Films by Hot Filament Chemical Vapor Deposition Method[D]. Wuhan: Wuhan Institute of Technology, 2015.
[23] MOHAMMADINIA E, ELAHI S M, SHAHIDI S.Structural and Optical Properties of Ni-Embedded Hydrogenated Diamond-Like Carbon (Ni-DLC) Prepared by Co-Deposition of RF-Sputtering and RF-PECVD Method[J]. Materials Science in Semiconductor Processing, 2018, 74: 7-12.
[24] LIANG H T, YANG X, YUE C T, et al.A Comparative Friction and Wear Study of Diamond and Diamond-Like Carbon Films Against Cu[J]. Tribology International, 2024, 193: 109344.
[25] KUZMANY H, PFEIFFER R, SALK N, et al.The Mystery of the 1 140 cm-1 Raman Line in Nanocrystalline Diamond Films[J]. Carbon, 2004, 42(5/6): 911-917.
[26] CHEN C K, TANG B J, XU H, et al.Low-Defect Nanodiamonds and Graphene Nanoribbons Enhanced Electron Field Emission Properties in Ultrananocrystalline Diamond Films[J]. ACS Applied Electronic Materials, 2021, 3(4): 1648-1655.
[27] TAKABAYASHI S, JEŠKO R, SHINOHARA M, et al. Chemical Structural Analysis of Diamondlike Carbon Films: II. Raman Analysis[J]. Surface Science, 2018, 668: 36-41.
[28] NANDIHALLI N.Microwave-Driven Synthesis and Modification of Nanocarbons and Hybrids in Liquid and Solid Phases[J]. Journal of Energy Storage, 2025, 111: 115315.
[29] SARNO M, SENATORE A, SCARPA D, et al.“Green” Synthesis of Nanocarbons for Reduced Friction and Wear[J]. Lubricants, 2020, 8(2): 13.
[30] ZHANG H, SONG H, PANG M, et al.Tribological Performance of Microcrystalline Diamond (MCD) and Nanocrystalline Diamond (NCD) Coating in Dry and Seawater Environment[J]. Crystals, 2022, 12(10): 1345.
基金
国家自然科学基金(52475231); 宁波市科技创新2035重大项目(2024Z097); 宁波市科技创新2025重大项目(2023Z009)