摘要
铝合金具有容重小、比强度高、耐大气腐蚀性好、导热性好、易成形加工、易回收利用等优点,其用量已成为仅次于钢铁的第二大金属材料。铝合金汽缸体由于质轻,能降低车身自重,减少了汽车摩托车的排放污染而在汽车摩托车行业得到广泛应用。但是,缸体-活塞摩擦副的工作环境恶劣,对汽缸体的内壁耐磨、耐热腐蚀性要求较高,因此必须对全铝合金缸体的内壁进行表面处理,从而提高其耐磨、耐蚀性。
在众多的表面处理技术中,复合电镀具有工艺简单、成本低、发展潜力大等优点,因而成为对全铝合金缸体的内壁表面处理的可选工艺之一。为了进一步提高镀层的性能,同时为了探索纳米材料在复合镀层中的工业应用,本课题研究了在Ni/微米SiC/纳米Al2O3复合电镀中,纳米微粒对镀层性能的影响,并对镀液成分和工艺参数进行了系统的试验和研究。另外本文还探讨了复合镀层的强化机理和微粒的沉积方式。
通过研究,证实了纳米微粒的加入有利于复合镀层性能的提高,总结了镀液成分和电流密度、温度等工艺参数对镀层性能的影响规律,并得到了Ni/微米SiC/纳米Al2O3复合电镀的最佳镀液成分和工艺参数为:500g/L氨基磺酸镍、15g/L氯化镍、46g/L硼酸、27g/L微米SiC、15g/L纳米Al2O3、pH值为4、阳极氧化中间处理、温度为57、电流密度为20A/dm2、气体中等搅拌、搅拌间隙时间为40s、时间30min。
同时,研究结果表明,复合镀层的强化机理应从基质金属的强化机理和微粒的强化机理两方面讨论。基质金属的强化机理可用位错理论来分析。微米微粒的强化机理则主要归功于微粒的弥散强化作用。纳米微粒对于镀层的强化机理有三:提高了镀层中微粒的沉积量、比微米微粒更为显著的弥散强化效果、纳米微粒的尺寸效应导致了基质镍金属中位错亚结构尺寸发生明显的变化。
因为纳米微粒是吸附在微米微粒周围,同时沉积在工件上,所以纳米微粒在沉积过程中没有发生大的团聚,在镀层里则是均匀地分布在微米微粒之间的间隙中。
Aluminum and its alloys are widely used in manufacturing industry to follow the iron and steel in market consumption, because it has a series of excellent properties, such as low density, high specific strength, corrosion-resistant ability in atmosphere, good diathermancy, easily forming, easily reproducing, etc. The aluminum alloy cylinder is widely used in diesel and gasoline engines for its low density and high specific strength to reduce the vehicles' weight. But unfortunately aluminum alloy appears poor wear-resistant and corrosion-resistant. Therefore, aluminum alloy must be surface-treated in order to improve the performances of wear resistant and corrosion resistant.
In all kinds of surface treatment technology, composite electroplating is one of feasible techniques on the surface of the aluminum alloy cylinder bore, because it has a series of excellent characteristics, such as simple techniques, low cost, tremendous development potential, etc. In order to improve the coating properties and seek after application of nanometer particles on composite coating, the effect of nanometer particles on the coating properties in Ni/micron SiC/nanometer Al2O3 is studied in this work. At the same time, electrolyte composition and processing parameters, such as electric current density, temperature, etc, are studied and analyzed. In addition, strengthen mechanism of coating and depositing way of particles is also discussed.
It has been concluded in this work that the coating properties can be improved by adding nanometer particles, and the relations between all kinds of processing parameters and coating properties are studied. Simultaneously, the electrolyte composition and the processing parameters of Ni/micron SiC/nanometer Al2O3 composite electroplating are obtained: 500 g/L Nickel Sulfamate, 15 g/L Nickel Chloride, 46 g/L boric acid, 27 g/L micron SiC, 15 g/L nanometer Al2O3, PH≈4, anodizing pre-treatment, treat temperature 57℃, electric current density 20A/dm2, mild intensity air stirrer, stirrer intermittent time 40 s, treat time 30 min.
At the same time, experimental results showed that the strengthen mechanism of coating are mainly composed of two aspects: the strengthen mechanism of nickel and the strengthen mechanism of particles. The strengthen mechanism of nickel is explained with dislocation theory. The strengthen mechanism of micro particles is due to dispersion strengthening. The strengthen mechanism of nanometer particles can be
contributed to three reasons: improvement of particles deposit, dispersion strengthening rather than micro particles, notability transformation of nickel dislocation sub-structure led by dimension domino effect of nanometer particles.
Because nanometer particles are adhibitting on the surface of micro particles, and both of them are deposited at one time, there is no big aggregation of nanometer particles, and nanometer particles take a condition of homogeneous distribution within the interspace of micro particles.
引文
[1] 旷亚非,许岩,李国希铝及其合金材料表面处理研究进展.电镀与精饰, 2000.22(1).16~20
[2] Hinton B R,Amott O R,Ryan N E.Cerinm Conversion Coatings for the corrosion protection of aluminum. Mater. Forum.1986,9(3).162
[3] Wirtz G P, Brown S D, Kriven W M. Ceramic coatings by anodic spark deposition. Materials and Manufacturing Processes.1991.6(1).87.
[4] 杨蔺孝等.铝材耐磨耐烧蚀特种氧化成膜机理的研究与应用.电镀与环保.1992.12(2).13
[5] 沈启贤.一种可取代电镀铬和化学镀镍的新型镀层.重型汽车.1996.5.19~21
[6] A.Leyland.Thin Tribological Coating: Magic or Design?.Surface Engineering.1991(7).247
[7] 李国英等.表面工程手则.北京.机械工程出版社.1997,8.6-115~6-133
[8] W.Metzger,R.Ott,G.Pappe,H.Schmidt. US Pat.3617363.1949
[9] 沃尔夫冈.里德尔著.罗守福译.顾明元校.化学镀镍.上海交通大学出版社.1996,10
[10] 华希俊.电刷镀耐磨减磨复合镀层研究.江苏理工大学学报.1999.3.40~45
[11] 车承焕.日本电镀技术及其发展方向.材料保护.1991.1.39~43
[12] 郭忠诚等.电沉积多元复合镀层的研究现状.电镀与环保.2001.21(2).4.
[13] 赵渠森.复合材料.国防工业出版社.1979
[14] G.R.Smith,J.E.Allison. Alloy coating method. US Pat.4601795.1986
[15] 徐龙堂.电刷镀镍基含纳米粉复合镀层性能、结构、和共沉积机理[学位论文].北京工业大学博士学位论文.2000,5,20
[16] 钱苗根.材料表面技术及其应用手册.北京.机械工业出版社.1998,10
[17] 吴玉程.复合材料镀层的制备和性能.机械工程材料.1990.78.45
[18] F.Garry. Overview of Brush Plating and Present Technology &Expertise.The AESF Annual Technical Conference. Orlando, USA.1993. 1161
[19] 万怡灶.电沉积法制备金属基复合材料的发展动态.材料导报.1997.11(2).64
[20] B.Szczygiet. Nickel Silicon Carbide Dispersion Layers on Aluminum. Metalloberflaeche. 1993.47(4).186
[21] A.Hovestad. Electrochemical Codeposition of Inert Particles in a Metallic Matrix. Journal of Applied Electrochemistry.1995.25(6).519
[22] G.Bapu. Electrocodeposition and Characterization of Nickel-Titanium Carbide Composites. Surface & Coatings Technology.1994.67(1-2).105
Y.Hong. Wear Resistance Characteristics of Electroless Deposited Ni-P-B4C Coating. Acta
[23] Materiae Compositate.1995.12(4).30
[24] P.Malathly. Nickel-Diamond Powder Electrocomposites. Metal Finishing.1997.94(11).22
[25] 吴玉程,邓宗钢等.复合材料的形成与功能.电镀与涂饰.1996.9.37~43
[26] 冶银平等.含纳米金刚石复合镍刷镀层的摩擦学性能.表面技术.1996.25(4).27
[27] 张新,余基来等.复合电镀(Ni-P)-SiC的新工艺.电镀与精饰.1996.3.12~14
[28] 刘国钦.Ni-金刚石复合镀层研究.表面技术.1991.20(3).18
[29] L.X.Hong. The Properties of Ni-Co-SiC Composite Coating. Metal Finishing.1994.92(11).76
[30] 高家峰等.新型耐磨滋润滑分散电刷镀.表面技术.1995.24(6).25
[31] 阎逢元等.一种新型的减摩耐磨复合镀层.材料研究学报.1994.8(6).573
[32] Bibber J W. A chromium-free conversion coating for creating a corrosion resistant aluminum. Met.Finish.1993.91 (12). 46
[33] Yoshikawa. Codeposition Mechanism of Zircomia Fine Particles in Electroless Plating Solutions. Journal of the Japan Society of Powder and Powder Metallurgy.1994.41(6).644
[34] Takahashi. Development of Cross-sectional TEM Analysis Techniques for Coated Steel Sheets. Nippon steel Technical Report.1994.63.53
[35] S W Banovic. Graded Ni-alumna coatings via Electrodeposition. Proceedings of the 125th TMS Annual Meering.USA.1996.89
[36] F.Yamaguchi. Studies on the Co-deposition Mechanism of Ni-TiO2. Journal of the Surface Finishing Society of Japan.1996.47 (5). 453
[37] J.P.Celis. Mechanism of Electrolytic Composite Plating:Survey and Trends. Trans.Inst.Metal Finish. 1991 69(4). 133
[38] J.Franser. Mechanisms of Composite Electroplating. Metal Finishing.1993.43 (6). 97
[39] A.Grosjean. Adaptation of a Mathematical Model to the Incorporation of SiC Particles in an Electroless Nickel Deposit. Metal Finishing.1998.95 (4). 14
[40] 杜克勤等.复合电沉积机理研究进展.电镀与金饰.1995.17(6).21
[41] 彭群家等.复合电沉积的研究及进展.电镀与环保.1998.18(6).3
[42] G.N.K.Ramesh. Characteristics of Ni-BN Electro-composites. Plating and Surface Finishing. 1995.82(4).70
[43] K.Hellem. Electrodeposition of Composite Layers. Finishing.1997.21 (1). 28
[44] G.Z.Cheng. Microstructure of Electrodeposited Ni-W-P-SiC Composite Coatings. Transactions of Nonferrous Metals Society of China (English Edition). 1997.7(1). 22
[45] Lin H.Y. Nanometer sized Materials and Nanotechnology. Materials Revies.1993.6.42
[46] H.Gleiter. XRD Studies of the Structure of Nanometer-sized Crystalline Materials. Phy.Rev. 1982.B35.9085
[47] W.Li. Properties of Nanomaterial. Modern Chemical Industry.1999.19 (6). 34
[48] 卢柯等.纳米晶体材料的Hall-Petch关系.材料研究学报.1994.8(3). 385
[49] H.I.Smith. Fabrication of Nanometer Scale Microstructure. Physics Tody.1990.2.42
[50] 严东生.纳米材料的合成与制备.无机材料学报.1995.10(1).1
[51] 王丹红.美国政府资助纳米前沿研究.科技时报.2000.4.20.
[52] 张立德.纳米材料学.辽宁科学技术出版社.1994.4
[53] 李春忠.国外纳米材料制备及应用领域评述.首届全国纳米材料技术应用研究会.1997.10
[54] A.Alfantazi. Synthesis of Nanocrystalline Zn-Ni Alloy Coatings. Journal of Materials Science Letters.1996.15 (15). 1361
[55] 张立德.纳米材料应用机遇与挑战.首届全国纳米技术应用研究会.1997.1
[56] B.Mueller.Al2O3-nanoparticle distribution in Plated Nickel Composite Films. Nanostructured Materials.1998.10 (8). 1285
[57] E.J.Podlaha. Pulse-reverse Plating of Nano composite Thin Films. Journal of the Electroche- mical Society.1997.144(7).200
[58] 高濂等.纳米结构陶瓷材料的进展、技术关键和应用前景.首届全国纳米材料技术应用研究会.1997.48
[59] T.Louis. Production F/A-18S Incorporate RAM. Aviation and Apace Technologu.1995.9.93
[60] 张振忠等.块状金属纳米材料的制备技术进展及展望.兵器材料科学与工程.1999.22(3).46
[61] 方亮等.雷达吸波材料的现状和展望.武汉工业大学学报.1999.21(6).21
[62] 孟凡文等.纳米复合隐身材料.西安工业学院学报.1999.19(4).22
[63] 林鸿溢.纳米技术及其军事应用.首届全国纳米材料技术应用研究会.1997.127
[64] 陈平.纳米粉末的分散技术和表面处理技术.首届全国纳米材料技术应用研究会.1997.175
[65] 李春华.俄罗斯的纳米级超细粉材料.材料导报.1995.2.75
[66] Q.Ouyang. Nano-ball Bearing Effect of Ultra-fine Particles of Cluster Diamonds. Applied Surface Science.1994.78.309
[67] 吴玉程.纳米功能涂层材料设计、性能及应用前景.首届全国纳米材料技术应用研究会.1997.97
[68] Yucong Wang, Simon C.Tung. Scuffing and wear behavior of aluminum piston skirt coatings against aluminum cylinder bore. Wear.1999.225-229.1100~1108
[69] I.Garcia, J.Fransaer, J.-P.Celis. Electrodeposition and sliding wear resistance of nickel composite coatings containing micron and submicron SiC particles. Surface and Coatings Technology. 2001.148.171~178
[70] 覃奇贤,郭鹤桐,刘淑兰等.电镀原理与工艺.天津.科学技术出版社.1993
[71] B.И.赖依聂尔著.耿文范译.轻合金的电镀层.中国工业出版社.1962
[72] Cohen S M. Review: Replacements for chromium pretreatment on aluminum. Corrsosion. 1995.51(1).71.
[73] 黄安,高军等.表面活性剂在复合电镀中的作用.电镀与环保.1996.5.6~8
[74] Sheng-Chang Wang, Wen-Cheng J.Wei. Kinetics of electroplating process of nano-sized ceramic particle/Ni composite. Materials Chemistry and Physics.2002.9286.1~7
[75] 张义成,封万起等.氨基磺酸镀镍层内应力的影响因素分析.材料保护.1996.3.5~7
[76] 黄辉,林志成等.镍-碳化硅复合电镀的研究.湖南大学学报.1996.8(4).57~61
[77] M.R.Mcgurk. Exploration of the Plate Bending Model for Predicting the Hardness Response of Coated system. Surface and Coatings Technology.1997.92.87
[78] 刘国勋.金属学原理.冶金工业出版社.1980.207
[79] G.K.Williamson. The Properties of Metal. Phil. Magazine. 1956.1.34
[80] 郑明新.工程材料.清华大学出版社.1993.86
[81] 彭晓,马信清等.Ni-La2O3复合镀层中的质点弥散与组态研究.中国腐蚀与防腐学报.1995.6.93~99
[82] F.J.汉姆弗斯.位错与硬粒子的交互作用.材料科学与工程.1991.6.48
[83] L.Orlovskaja, N.Periene, M.Kurtinaitiene, G.Bikuloius. Electrocomposites with SiC content modulated in layers. Surface and Coatings Technology.1998.105.8~12
[84] 黄新民,吴玉程,郑玉春.纳米颗粒对复合镀层性能的影响.兵器材料科学与工程.1999.11(6).11~14
[85] 王玉林,赵乃勤等.Al2O3颗粒粒径和含量对α-Al2O3/Cu复合镀层性能的影响.复合材料学报.1998.2.78~82
[86] 平荣刚,郑瑞伦.复合镀层硬度与其添加微粒含量的关系.重庆师范学院学报(自然科学版).1998.3.61~65
[87] 梁玉平.陶瓷纳米复合材料.材料工程.1994.6.1~4
[88] R.J.Arsenault. Research Progress of Metal Matrix Material Composites Reinforced with Particles. Sci.Eng.1994 (81). 175
[89] O.Berkin. Properties of Electrodeposited NiP-SiC Composite Coating. Metal Finishing. 1996.93(6).35
[90] 郭鹤桐.复合镀层.天津大学出版社.1991.35
[91] 黄新民,吴玉程,郑玉春,张勇.分散方法对纳米颗粒化学复合镀层组织及性能的影响.电镀与精饰.1999.9.12~15