Tribological properties of ionic liquid modified MWCNTs, MoS2, and their composite nanofluids
-
摘要: 采用1-乙基-3-甲基咪唑四氟硼酸鹽（[EMIm]BF4）離子液體分散多壁碳納米管（MWCNTs）、二硫化鉬（MoS2）于去離子水以得到具有優異摩擦學特性的納米流體。通過拉曼光譜儀、納米粒度電位儀、接觸角測量儀表征其分散與潤濕性，通過導熱系數儀和流變儀測試其熱物性，并通過材料表面性能綜合測試儀進行摩擦實驗。結果表明：經[EMIm]BF4改性而制備的納米流體Zeta電位大幅提高，納米顆粒在空間位阻作用下有效分散于水基液，故保持潤濕性的同時增強了導熱能力，其對高溫合金的潤濕接觸角最小為59.33°，室溫(25 °C)平均黏度最低為1.49 mPa·s，且導熱系數最大為1.02 W·(m·K)–1。納米流體中層狀、管狀幾何結構的MoS2、MWCNTs納米顆粒極大強化了基液的減摩抗磨性能，平均摩擦系數降至0.083，磨痕體積磨損率相比傳統水基冷卻液減小了72.33%。Abstract: The machining process is generally accompanied by intense friction and heat generation. Excessive heat flux subsequently leads to thermal damage and shape defects on the workpiece, which will greatly reduce the service life of the tool. As a novel coolant, nanofluids can effectively improve the lubrication and cooling conditions in precision machining. This paper uses the ionic liquid 1-ethyl-3-methylimidazole tetrafluoroborate ([EMIm]BF4) to disperse multi-walled carbon nanotubes (MWCNTs) and molybdenum disulfide (MoS2). The nanofluid with excellent tribological properties was prepared. The crystal structure of nanoparticles was analyzed by an X-ray diffractometer (XRD). The wettability and particle dispersibility of nanofluids were characterized by a Raman spectrometer, nanoparticle size potential analyzer and contact angle measuring instrument. Thermophysical properties were tested by a thermal conductivity measuring instrument and rheometer. Finally, a friction and wear tester and an ultra-depth-of-field microscope were used to analyze the friction properties of the prepared nanofluids. The following results are obtained. (1) After the MWCNTs or MoS2 nanoparticles are modified by the adsorption of [EMIm]+ cations, the Zeta potential of the nanofluids is greatly increased, and the laminated structure formed by the adsorption of two nanoparticles increases the particle size distribution range. By this time, an electrostatic equilibrium area is formed around the nanoparticles, whereby the particles are effectively dispersed due to the steric hindrance effect. (2) MWCNTs, MoS2, and their composite nanofluids are determined as pseudoplastic fluids, which are easy to spread and form films on metal (superalloy GH4169) surfaces with a minimum contact angle of 59.33°. After testing, the addition of nanoparticles and dispersants in the nanofluids did not cause a sharp increase in the viscosity, and the average viscosity was found to be as low as 1.49 mPa·s (25 °C), thus maintaining the flow advantages of water-based coolants while obtaining a higher thermal conductivity [up to 1.02 W·(m·K)?1 (25 °C)]. This is suitable for machining fields that require efficient flow heat transfer. (3) MWCNTs, MoS2, and their composite nanofluids greatly enhance the anti-friction and anti-wear properties of the base fluid (deionized water), especially composite nanofluids containing two nanoparticles, which form a “bearing-like” effect by stacking the layered and tubular combined structures. Thus, the lubrication performance is optimal. Compared with the traditional water-based coolant, the average friction coefficient of the composite nanofluid is small (0.083). At the same time, the adhesive wear or abrasive wear on the surface of the workpiece is further reduced, the wear scar is narrow and shallow, and the volume wear rate is reduced by 72.33%.
-
Key words:
- ionic liquid /
- nanofluid /
- multi-walled carbon nanotubes /
- molybdenum disulfide /
- tribology
-
圖 1 復合流體中MWCNTs/MoS2疊層結構示意
Figure 1. Schematic diagram of the MWCNTs/MoS2 sandwich structure in a composite fluid
圖 2 納米顆粒顯微形貌. (a) MoS2; (b) MWCNTs
Figure 2. Microscopic morphology of nanoparticles: (a) MoS2; (b) MWCNTs
圖 3 納米顆粒的XRD譜圖. (a) MWCNTs; (b) MoS2
Figure 3. X-ray diffraction spectra of nanoparticles: (a) MWCNTs; (b) MoS2
圖 4 納米顆粒的拉曼光譜. (a) [EMIm]BF4改性的MWCNTs; (b) [EMIm]BF4改性的MoS2
Figure 4. Raman spectra of nanoparticles: (a) [EMIm]BF4 modified MWCNTs; (b) [EMIm]BF4 modified MoS2
圖 6 不同流體在高溫合金基底表面的接觸角
Figure 6. Contact angle of different fluids on the surface of the superalloy substrate
圖 7 不同流體的熱物性測試結果. (a)黏度; (b)導熱系數
Figure 7. Test results of thermophysical properties of different fluids: (a) viscosity; (b) thermal conductivity
圖 8 摩擦系數曲線與平均摩擦系數分布. (a) 摩擦系數變化曲線; (b) 平均摩擦系數分布
Figure 8. Friction coefficient curve and average friction coefficient distribution: (a) variation curve of friction coefficient; (b) average friction coefficient
圖 9 不同潤滑條件下的基底磨痕形貌及其三維輪廓. (a)H2O; (b) ILs; (c) 傳統水基冷卻液; (d) MoS2納米流體; (e)MWCNTs納米流體; (f) 復合納米流體
Figure 9. Wear morphology and its three-dimensional profile under different lubrication conditions: (a)H2O; (b) ILs; (c) conventional coolant; (d) MoS2 nanofluid; (e)MWCNTs nanofluid; (f) composite nanofluid
圖 10 不同潤滑條件下體積磨損率分布
Figure 10. Distribution of the volume wear rate under different lubrication conditions
表 1 納米顆粒的物理參數
Table 1. Physical parameters of nanoparticles
Nanoparticles Size / nm Aspect ratio Tap density / (g?cm?3) Purity / % MWCNTs 30–50 (OD) 16.67–66.67 0.27 99.5 MoS2 50 — 0.912 99.9 Note: OD is outer diameter. 
下載: 導出CSV
表 2 ILs的物理參數
Table 2. Physical parameters of ILs (25 °C, 0.1 MPa)
Density / (g?mL?1) Viscosity / (Pa·s) Specific heat capacity / (J?K?1?mol?1) Surface tension / (N?m?1) 1.285 0.039 305 0.054
下載: 導出CSV
表 3 GCr15軸承鋼的主要化學組成（質量分數）
Table 3. Main chemical composition of the GCr15 bearing steel
% Element Cr C Mn Si Ni Cu Fe Content 1.4–1.65 0.95–1.05 0.25–0.45 0.15–0.35 ≤0.3 ≤0.25 Bal.
下載: 導出CSV
表 4 鎳基高溫合金GH4169的主要化學組成（質量分數）
Table 4. Main chemical composition of the GH4169 superalloy
% Element Ni Cr Nb Mo Ti Al Fe Content 53.4 18.8 5.27 2.99 1.02 0.50 Bal.
下載: 導出CSV
中文字幕在线观看表 5 納米流體的粒徑分布
Table 5. Particle size distribution in the nanofluid
nm Nanofluid Range of particle size Average particle size MWCNTs 890.1–1203.2 923.3 MoS2 46.5–531.4 427.1 Composite 141.8–1055.4 447.8
下載: 導出CSV
-
參考文獻
[1] Ding Z S, Sun G X, Guo M X, et al. Effect of phase transition on micro-grinding-induced residual stress. J Mater Process Technol, 2020, 281: 116647 doi: 10.1016/j.jmatprotec.2020.116647 [2] Singh H, Sharma V S, Singh S, et al. Nanofluids assisted environmental friendly lubricating strategies for the surface grinding of titanium alloy: Ti6Al4V-ELI. J Manuf Process, 2019, 39: 241 doi: 10.1016/j.jmapro.2019.02.004 [3] Qureshi M Z A, Bilal S, Chu Y M, et al. Physical impact of nano-layer on nano-fluid flow due to dispersion of magnetized carbon nano-materials through an absorbent channel with thermal analysis. J Mol Liq, 2021, 325: 115211 doi: 10.1016/j.molliq.2020.115211 [4] Huang Y Y, Li G H, Zhao B, et al. Preparation and energy storage properties of V2O5/MXene nanocomposites. Chin J Eng, 2020, 42(8): 1018黃瑩瑩, 李庚輝, 趙博, 等. V2O5/MXene納米復合材料制備及儲能性能. 工程科學學報, 2020, 42(8):1018 [5] Saad I, Maalej S, Zaghdoudi M C. Electrohydrodynamic effects on a nanofluid-filled flat heat pipe. Therm Sci Eng Prog, 2020, 16: 100426 doi: 10.1016/j.tsep.2019.100426 [6] Khatai S, Kumar R, Sahoo A K, et al. Metal-oxide based nanofluid application in turning and grinding processes: A comprehensive review. Mater Today Proc, 2020, 26: 1707 doi: 10.1016/j.matpr.2020.02.360 [7] Fukushima T, Kosaka A, Ishimura Y, et al. Molecular ordering of organic molten salts triggered by single-walled carbon nanotubes. Science, 2003, 300(5628): 2072 doi: 10.1126/science.1082289 [8] Pan W X, Zhang D J, Sun H, et al. Theoretical study of the interaction mechanism between single-walled carbon nanotubes and imidazolium-based ionic liquids. Sci Sin (Chimica) , 2011, 41(1): 51 doi: 10.1360/032010-22潘文筱, 張冬菊, 孫慧, 等. 碳納米管與咪唑類離子液體相互作用機制的理論研究. 中國科學:化學, 2011, 41(1):51 doi: 10.1360/032010-22 [9] Maiyelvaganan K R, Kamalakannan S, Prakash M. Adsorption of ionic liquids on carbonaceous surfaces: The effect of curvature on selective anion···π and cation···π interactions. Appl Surf Sci, 2019, 495: 143538 doi: 10.1016/j.apsusc.2019.143538 [10] Wang G S, Wang X Y. Influence of medium-low concentration of ionic liquid[bmim][BF4]on critical micellization concentration and micelle structures. Chemistry, 2017, 80(8): 777王冠石, 王小永. 添加中低濃度離子液體[bmim][BF4]對吐溫-20臨界膠束濃度和膠束結構的影響. 化學通報, 2017, 80(8):777 [11] Che Q L, Li H, Zhang L G, et al. Role of carbon nanotubes on growth of a nanostructured double-deck tribofilm yielding excellent self-lubrication performance. Carbon, 2020, 161: 445 doi: 10.1016/j.carbon.2020.01.091 [12] Junankar A A, Parate S R, Dethe P K, et al. A Review: Enhancement of turning process performance by effective utilization of hybrid nanofluid and MQL. Mater Today Proc, 2021, 38: 44 doi: 10.1016/j.matpr.2020.05.603 [13] Peng R T, Tong J W, Zhao L F, et al. Molecular dynamics study on the adsorption synergy of MWCNTs/MoS2 nanofluids and its influence of internal-cooling grinding surface integrity. Appl Surf Sci, 2021, 563: 150312 doi: 10.1016/j.apsusc.2021.150312 [14] Deng L F, Peng H Y, Qin Y K, et al. Combination carbon nanotubes with graphene modified natural graphite and its electrochemical performance. J Mater Eng, 2017, 45(4): 121鄧凌峰, 彭輝艷, 覃昱焜, 等. 碳納米管與石墨烯協同改性天然石墨及其電化學性能. 材料工程, 2017, 45(4):121 [15] Li K, Liu Q F, Cheng H F, et al. Classification and carbon structural transformation from anthracite to natural coaly graphite by XRD, Raman spectroscopy, and HRTEM. Spectrochimica Acta A Mol Biomol Spectrosc, 2021, 249: 119286 doi: 10.1016/j.saa.2020.119286 [16] Shi S C, Wu J Y, Huang T F. Raman, FTIR, and XRD study of MoS2 enhanced hydroxypropyl methylcellulose green lubricant. Opt Quantum Electron, 2016, 48(10): 1 [17] Patil S S, Koinkar P M, Dhole S D, et al. Influence of high-energy electron irradiation on field emission properties of multi-walled carbon nanotubes (MWCNTs) films. Phys B Condens Matter, 2011, 406(9): 1809 doi: 10.1016/j.physb.2011.02.033 [18] Najmaei S, Liu Z, Ajayan P M, et al. Thermal effects on the characteristic Raman spectrum of molybdenum disulfide (MoS2) of varying thicknesses. Appl Phys Lett, 2012, 100(1): 013106 doi: 10.1063/1.3673907 [19] Li H, Zhang Q, Yap C C R, et al. From bulk to monolayer MoS2: Evolution of raman scattering. Adv Funct Mater, 2012, 22(7): 1385 doi: 10.1002/adfm.201102111 [20] Hou J J, Sui H, Du J Z, et al. Synergistic effect of silica nanofluid and biosurfactant on bitumen recovery from unconventional oil. J Dispers Sci Technol, 2020: 1 [21] Sun H J, Chen J J, Huang Z X, et al. Selective hydrogenation of benzene to cyclohexene over the nano-sized Ru–Zn catalyst modified by Arabic gum. Chin J Inorg Chem, 2016, 32(2): 202孫海杰, 陳建軍, 黃振旭, 等. 阿拉伯樹膠修飾的納米Ru–Zn催化劑上苯選擇加氫制環己烯. 無機化學學報, 2016, 32(2):202 [22] El?i?ek H, Güzel B. Effect of shear-thinning behavior on flow regimes in Taylor-Couette flows. J Non Newton Fluid Mech, 2020, 279: 104277 doi: 10.1016/j.jnnfm.2020.104277 [23] Zhu Y F, Zamani M, Xu G Y, et al. A comprehensive experimental investigation of dynamic viscosity of MWCNT–WO3/water–ethylene glycol antifreeze hybrid nanofluid. J Mol Liq, 2021, 333: 115986 doi: 10.1016/j.molliq.2021.115986 [24] Vadasz P. Heat conduction in nanofluid suspensions. J Heat Transf, 2006, 128(5): 465 doi: 10.1115/1.2175149 [25] Xie G X, Luo J B, Guo D, et al. Film forming characteristics of common ionic liquid lubricants. J Mech Eng, 2011, 47(11): 82 doi: 10.3901/JME.2011.11.082解國新, 雒建斌, 郭丹, 等. 普通離子液體潤滑劑的潤滑成膜性能研究. 機械工程學報, 2011, 47(11):82 doi: 10.3901/JME.2011.11.082 [26] Han X, Thrush S J, Zhang Z P, et al. Tribological characterization of ZnO nanofluids as fastener lubricants. Wear, 2021, 468-469: 203592 doi: 10.1016/j.wear.2020.203592 [27] Liu W M, Xue Q J, Zhou J F, et al. Antiwear properties of nanoparticles and application study of nanoparticles as additives in the wear-repairing agent. China Surf Eng, 2001, 14(3): 25劉維民, 薛群基, 周靜芳, 等. 納米顆粒的抗磨作用及作為磨損修復添加劑的應用研究. 中國表面工程, 2001, 14(3):25 [28] Upadhyay R K, Kumar A. Boundary lubrication properties and contact mechanism of carbon/MoS2 based nanolubricants under steel/steel contact. Colloid Interface Sci Commun, 2019, 31: 100186 doi: 10.1016/j.colcom.2019.100186 [29] Wang X L, Xu B S, Xu Y, et al. Study on friction and wear behavior and mechanism of nano-Cu additive in lubrication oils. Tribology, 2007, 27(3): 235王曉麗, 徐濱士, 許一, 等. 納米銅潤滑油添加劑的摩擦磨損特性及其機理研究. 摩擦學學報, 2007, 27(3):235 -
點擊查看大圖
計量
- 文章訪問數: 707
- HTML全文瀏覽量: 246
- PDF下載量: 62
- 被引次數: 0
