Ni-P coating

Fig. 31—Surface AFM image for Ni-P coating polished by AI2O3 slurry.

Poon, C. Y. andBhhushan, B., Surface Roughness Analysis of Glass-Ceramic Substrates and Finished Magnetic Disks, and Ni-P Coated Al-Mg and Glass Substrates," Wear, Vol. 190, 1995,pp. 89-109. 

The incorporation of a third element, e.g. Cu, in electroless Ni-P coatings has been shown to improve thermal stability and other properties of these coatings [99]. Chassaing et al. [100] carried out an electrochemical study of electroless deposition of Ni-Cu-P alloys (55-65 wt% Ni, 25-35 wt% Cu, 7-10 wt% P). As mentioned earlier, pure Cu surfaces do not catalyze the oxidation of hypophosphite. They observed interactions between the anodic and cathodic processes both reactions exhibited faster kinetics in the full electroless solutions than their respective half cell environments (mixed potential theory model is apparently inapplicable). The mechanism responsible for this enhancement has not been established, however. It is possible that an adsorbed species related to hypophosphite mediates electron transfer between the surface and Ni2+ and Cu2+, rather in the manner that halide ions facilitate electron transfer in other systems, e.g., as has been recently demonstrated in the case of In electrodeposition from solutions containing Cl [101]. 

Nickel deposits have unique magnetic properties, except deposits containing more than 8 percent phosphorus are essentially nonmagnetic. In Ni-P coatings, phosphorus is present as supersaturated solution in fine microcrystalline solid solution, bordering on amorphous or liquid-like (glass-like) metastable structure, and this phosphorus is... 

N. El Mahallawy, A. Bakkar, M. Shoeib, H. Palkowski and V. Neubert, Electroless Ni-P coating of different magnesium alloys . Surface and Coatings Technology, 202, (2008), 5151-5157. 

Figure 1.6 SEM images of worn surface of Ni-P coatings (d) and Ni-P coatings containing (b) 2H-...

The focus of this study is to evaluate the influences of the Ni-P coatings on the fiber surfaces properties and thermomechanical properties of composites with polyester resin. 

Fig. 2 shows the variation of loss modulus with temperature for Ni-P coated samples. Loss modulus also increases for higher Ni-P coating times. A shift in peak is also seen here indicating an improvement in Tg. 

Figure 1. Temperature dependence storage modulus of Ni-P coated composites for different coating time in bending mode...

Key words Ni-P coating, wet lay-up process, DMA, Modulus, Glass transition temperature (Tg)... 

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