Electroplating composites

PSF-ABS similar to PC-ABS, composition can be electroplated due to ABS, lower cost than polysulfone plumbing fixtures, food service trays, apphances 334... 

Cadmium, cobalt, copper, and nickel sulfamates react with lower aHphatic aldehydes. These stable compositions are suitable for use ia electroplating solutions for deposition of the respective metal (see Electroplating). 

Because of the ease with which they can be soldered, electroplated tin—lead coatings of near eutectic composition (62 wt % tin) are extensively used in the electronics industry for coating printed circuit boards and electrical coimectors, lead wires, capacitor and condenser cases, and chassis. 

Table 8. Chemical Composition and Operating Parameters for Chromium Electroplating Baths...

In electroplating processes, cinnamaldehyde is utili2ed as a hrightener (35). Other appHcations include its efficacy as an animal repellent (36), its use in compositions to attract insects (37), and demonstration of a positive antiflmgal activity (38). 

In a permeation experiment, an HERO module with a membrane area of 200 m is used to remove a nickel salt from an electroplating wastewater. TTie feed to the module has a flowrate of 5 x IQ— m /s, a nickel-salt composition of 4,(X)0 ppm and an osmotic pressure of 2.5 atm. The average pressure difference across the membrane is 28 atm. The permeate is collected at atmospheric pressure. The results of the experiment indicate that the water recovery is 80% while the solute rejection is 95%. Evaluate the transport parameters Ay and (D2u/KS). 

Titanium is a very difficult metal to electroplate because of the presence of an oxide film. Sophisticated pretreatments with acids to remove the oxide film are necessary to achieve good adhesion. Improvements in the level of adhesion can, however, be obtained by heat treatment of the resultant Pt/Ti composites... 

The metallic substrate, clean and rinsed, is immersed wet in the plating cell. The base metals which are usually plated present an essentially metallic surface to the electrolyte, and the slight corrosive action of the rinse water in preventing the formation of any substantial oxide film is important. A critical balance of corrosion processes in the initial stages is vital to successful electroplating, and for this reason there is a severe restriction on the composition of the electroplating bath which may be used for a particular substrate. This will be discussed later. The substrate is made the cathode of the cell it may be immersed without applied potential ( dead entry) or may be already part of a circuit which is completed as soon as the substrate touches the electrolyte ( live entry). Live entry reduces the tendency for the plating electrolyte to corrode the substrate in the period before the surface... 

Plating baths contain a number of salts and compounds in addition to those of the ion to be reduced to metal. Much commercial electroplating is from proprietary solutions whose use is covered by patents, and which are supplied completely or partly compounded. The precise composition is generally a trade secret, and the patents may sometimes be very widely drawn to include a larger range of compositions and ingredients than is successful. A broad classihcation of additional ingredients includes ... 

Other alloy additions in commercial use include iron (often a two-layer electroplated coating with less iron—typically 20% —in the under-layer to assist formability and more iron—often 80% —in the outer layer to assist paintability) cobalt (0.15-0.35%) similar amounts of chromium (the zinc/ chromium/chromium-oxide coating known as Zincrox) and a range of ternary alloys and of composite coatings. 

The sulphate bath The sulphate bath, the earliest of electroplating solutions and the simplest in composition, contains typically 150-250 g/1 of copper sulphate and 40-120 g/1 of sulphuric acid. The composition is not critical and the higher concentrations are used for plating at higher current densities, normally up to 6 A/dm. ... 

Most nickel electroplating is carried out in solutions based oh the mixture of nickel sulphate, nickel chloride and boric acid proposed, by O. P., Watts . Typical composition and operating conditions are ... 

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