A study of electroless nickel coatings containing low phosphorus

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“…The results agreed with the studies from some other investigators showing that both the as-deposited medium [8,17,24] and low [22] phosphorus deposits consisted of a semi-amorphous structure. In the present study, the reflections that correspond to the 2θ region of nickel {111} and {200} planes are seen in the XRD Figure 3 XRD patterns of the electroless Ni-P deposit with 3-5 wt% P (LP sample) at as-deposited condition and after heating at 20 • C/min to the end temperatures 300 • C-800 • C. For the sake of clarity the XRD profiles were shifted arbitrarily on the vertical scale.…”

“…Since the first discovery by Brenner and Riddell in 1944 [6,7], various investigators have reported that the microstructural properties and crystallization behaviour of electroless Ni-P deposits depend on the phosphorus contents and heating processes of the deposits. However, many conflicting results have been reported from these studies [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. In general, the electroless Ni-P deposits can be classified as low (1-5 wt% P), medium (5-8 wt% P) and high (9 wt% P and more) phosphorus deposits based on their phosphorus contents [28].…”

“…In general, the electroless Ni-P deposits can be classified as low (1-5 wt% P), medium (5-8 wt% P) and high (9 wt% P and more) phosphorus deposits based on their phosphorus contents [28]. Studies have shown that the asdeposited low-phosphorus deposits consist of microcrystalline nickel [22] or crystalline phase [17,23]. The as-deposited medium-phosphorus deposits can be either amorphous [23] or mixtures of amorphous and microcrystalline nickel phases [8,17,24,26].…”

Surface characterization of zincated aluminium and selected alloys at the early stage of the autocatalytic electroless nickel immersion process

“…Kreye et al [8] and Zhang et al [9] described electroless nickel coatings with very low phosphorus content as equiaxed and nanocrystalline, while Yamasaki et al [10], Tyagi et al [11] and Hur et al [12], concluded that low phosphorus deposits are crystalline, containing a supersaturated solid solution of phosphorus in the nickel lattice. X-ray diffraction patterns obtained from electroless nickel deposits are known to change with heat treatment as it involves change in microstructure of the nickel matrix [13]. Teheri [14] concluded that the presence of many peaks is evidence of transformation from amorphous and non-crystalline to crystalline structure after heat treatment.…”

Combinatorial performance characteristics of agitated nickel hypophosphite electroless plating baths

“…Several experimental investigations on nickel hypophosphite plating baths emphasized with respect to the surface engineering studies (Lambert and Duquette, 1989;Baskaran et al, 2006;Li and An, 2008;Elansezhian et al, 2009;Liu et al, 2009), without giving much insight into the choice of various process parameters such as concentrations of nickel, hypophosphite and stabilizer, coating time, pH, temperature and loading ratio. Process engineering studies towards nickel electroless plating need to address simultaneously two objectives namely identification of optimal process parameters that maximize plating conversion and efficiency and quality of plating with respect to the substrate.…”