Watts plating bath

Nickel. Nickel plating continues to be very important. Many plating baths have been formulated, but most of the nickel plating is done in either Watts baths or sulfamate baths. Watts baths contain sulfate and chloride nickel salts along with boric acid, and were first proposed in 1916 (111). Nickel was first plated from sulfamate in 1938 (112) and patented in 1943 (108). The process was brought to market in 1950 (113). Typical bath compositions and conditions are shown in Table 14. 

A novel technology for preparation or Raney Ni composite coated electrodes for cathodic Hj evolution was described by Choquette et al. (181). A Raney Ni/Al powder is introduced into a Watts Ni-plating bath, and the... 

Toagosei Chemical Company and Chlorine Engineers Corporation jointly developed Ni-C dispersion electroplated cathodes, named TWAC, in the 1980s [198-200]. The Ni-C composite layer is applied to the nickel plated type 304 stainless steel substrate by dispersion electroplating. The Watts-type plating bath contains... 

Several plating baths are used. Three general purpose baths are commonly used Watts, Sulfa-mate and Fluoborate. The Watts bath contains the following ... 

Plating solutions used in nickel electroforming are primarily the Watts bath and the nickel sulfamate bath. Watts baths exhibit higher stress and require additives for stress control, which may affect other properties. Sulfamate baths produce much lower stress and are preferred where purer nickel or nickel—cobalt deposits ate needed. ASTM specifications are available that describe the mandrels and plating solutions (116,162). 

The basic bath has altered little since Watts introduced high-speed nickel plating in 1916. The bath is based on nickel(II) sulfate, nickel(H) chloride and boric acid. Whilst this offers little scope for novel coordination chemistry, the importance of nickel plating has ensured that more work than usual has been performed on addition agents25 and some aspects of this might be profitably considered. 

Alkaline CuCN solutions were used for the first time to electrodeposit homogeneous and adherent Cu films onto silicon. Tire obtained Cu/n-Si(lll) junctions show a nearly perfect rectifying behavior. The Schottky parameters (barrier height 3>b = 630 mV ideality factor n = 1.2) do not change importantly with time. It is also demonstrated that highly adherent Ni films can be plated onto n-Si(lll) from an acidic Watts bath, if copper clusters were elecrodeposited onto the silicon surface first. 

The excellent adherence of Cu layers gives the opportunity of preparing electroplated adherent films of various metals onto n-Si(lll), using a two step process in which Cu clusters are first grown as precursors and then, the metal of interest is plated. Figure 5 shows an in plane TEM view of Cu clusters electrodeposited on n-Si(lll) (Vd = -1.75 V, td = 40 s). They represent the minimum quantity of copper necessary to obtain nickel films from a modified Watts bath (pH 3). Nickel was electrocristallized at Vd = - 1.30 V and we emphasize that it was not possible to achieve Ni deposition on n-Si(lll) at this potential without the presence of Cu clusters. Ni films are also very adherent and they successfully passed the... 

S.4.2.3 Nickel-phosphorus Excellent corrosion protection is observed if the nickel layer contains phosphorus. This was first observed with electroless NiP layers (see Sect. 5.5.4.2.4). During the last years, electrochemical plating processes for nickel phosphorus have been developed. In these processes, a phosphorus source has to be added to the electrolyte either sodium phosphite or sodium hypophosphite are used. The other components of the electrolyte are similar to a Watts bath (see Sect. 5.S.4.2). Table 6 lists a typical composition. 

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