AbstractAn automatic brush plating system was developed to eliminate the disadvantages resulting from the operator in conventional brush plating.With this system, Ni/nano-Al2O3 composite coatings on 45 steel substrates were prepared from an electrolyte containing 20 g/l nano-Al2O3particles. For comparison, Ni/nano-Al2O3 composite coatings were also prepared manually. Microstructure, surface morphology, microhardness,modulus and wear resistance of two Ni–matrix composite coatings were investigated comparatively. 57203
Our present study shows that coatingprepared automatically is much more dense, smooth, and uniform than that prepared manually. The former exhibits better mechanical and anti-wear properties than the latter.© 2005 Elsevier B.V. All rights reserved.Keywords: Brush-plating; Automation; Composite coating 1. IntroductionCharles Dalloz and Georges Icxi designed the brush platingprocess in 1937 [1]. An important milestone in the developmentof brush plating process was that the first North Americancommercial specification was issued for brush plating in1956, thus formally recognizing brush plating process as aviable electroplating process. Today, brush plating has gainedwidespread applications in engineering, especially for repairand maintenance.Brush plating, also known as selective plating, or swabplating, is a very useful and portable method of contact plating.In its simplest form, the brush plating process resembles paint-ing. Brush plating equipment includes power packs, solutions,plating tools, anode covers, and auxiliary equipment. Thepower pack has two leads. One is connected to the platingtool and the other is connected to the workpiece to be plated.The anode is covered with an absorbent material which holdsthe solution. The operator dips the plating tool in the solutionand then brushes it against the surface of the workpiece that isto be finished. When the anode touches the work surface acircuit is formed and an electrodeposit is produced. Plating occurs only where the anode contacts the workpiece. Duringthe brush plating process, the plating tool is always kept inmotion whenever it is in contact with the work surface. Themovement will apply even plating on the entire area beingplated and ensure a quality finish. More detailed informationabout brush plating includes “Brush plating” by Norris [2], and“An update on brush plating” by Vanek [3].
Due to its portability, flexibility and easiness to operate,brush plating has found increasing use in industry. Dini [4]summarized quantitative property data on a variety of brush-plated deposits, which offer promise in applications involvingwear and/or corrosion resistance. Subramanian et al. [5,6]adopted brush plating technique to prepare tin selenide thinfilm on tin oxide coated conducting substrates at room temper-ature. Xu et al. [7] prepared Ni interlayer by brush platingbefore double glow plasma alloying of low carbon steel toenhance corrosion resistance. Hu et al. [8] used brush-platedNi–W coating as interlayer to improve the adhesion and wearresistance. Hui et al. [9] reported that the wear resistance ofbrush-plated alloy Ni–Fe–W–S was superior to that of anelectrodeposited chromium layer under dry friction at heavyload. Ma et al. [10] studied the tribological behavior of sulfu-rized olefin on Ni–P brush plating layers and found that thechemical reaction film NiS formed by the reaction of SO withNi–P plating layer on wear surfaces possessed very good anti-scuffing and anti-wear properties. Electrodeposited nickel composite coatings have widespreaduse in engineering, which conventionally have particles of adiameter ranging between 1 and 100 μm. There is now a trendto using nano-sized particles as the additional ingredient of thenickel composite. Du et al. [11,12] prepared nano-Al2O3/Nicomposite coatings by means of brush plating and found thatn-Al2O3/Ni composite coatings show improved tribologicalproperties under abrasive contaminant lubrication. Xu et al.[13] reported that the brush-plated nickel silica nano-compositecoatings possess finer crystal grains and the bonding betweenthe matrix metal Ni and the SiO2 ceramic particles is compact.Wang et al. [14] studied the micro mechanical properties ofnano-Al2O3/Ni composite coatings, such as hardness, elasticmodulus and indentation creep property by nanoindentationand found that the mechanical properties are basically identicalwithin the whole coating and the hardness is 源1自3优尔8.论~文'网·www.youerw.com  自动刷镀技术的革新英文文献和中文翻译:http://www.youerw.com/fanyi/lunwen_61807.html