scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Study on characterisation and influence of surfactants on adhesion and coating thickness of electroless Ni–P deposits

TL;DR: In this paper, two surfactants namely sodium dodecylsulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) were used in the characterization of electroless nickel-phosphorus (EN) deposits.
Abstract: Electroless nickel–phosphorus (EN) deposits with and without addition of surfactants were made on mild steel substrates. Two surfactants namely sodium dodecylsulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) were used in the study. The EN coated samples were characterized using X–ray diffraction analysis and transmission electron microscopy. The XRD pattern of all the deposits indicated the presence of crystalline and amorphous phases coexisting in the as deposited condition. Profile refinement techniques have been used to separate the crystalline nickel (111) reflection from the amorphous profile. The crystallite size of nickel was found to vary from 200 nm in the as deposited condition to 80 nm with addition of surfactant. TEM study reveals a nano crystalline structure of the deposit in as plated condition and an amorphous structure with addition of surfactants. With addition of surfactants adhesion was good. The coating thickness varied from 12.7 µm to 32.2 µm with addition surfactants.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, the authors investigated the influence of adding excess amount of reducing agent (RA) to the bath during the coating process to compensate for the consumed amount of electrons and found that the NRE was significantly increased from 35 to 61%.
Abstract: This research paper reports on the improvement of nickel recovery efficiency (NRE) and microhardness of the electroless Ni–P coating process. At present, in the electroless nickel coating process, the NRE is very low. Owing to this reason, the coating cost of electroless nickel is very high. Earlier researchers have tried to recover the nickel from the used bath after coating is completed and some achieved success in their attempt by further improving the nickel recovery from 25 to 35%. To overcome the above problem, the excess amount of reducing agent (RA) is supplied to the bath during the coating process to compensate for the consumed amount of electrons. The influence of adding excess amount of RA on NRE and other properties of the deposit have been investigated in this study. The NRE was significantly increased from 35 to 61%.The various coatings parameters used in the electroless bath were optimised to get the high NRE using a Taguchi optimisation technique.

32 citations


Cites background from "Study on characterisation and influ..."

  • ...The quality of coating is dependent upon the microstructure and composition of the deposits.(1) Electroless plating is widely applied to many industries because of its special advantages....

    [...]

Journal ArticleDOI
TL;DR: In this article, an electroless Ni-P coating process with propane sulfonate zwitterionic surfactant (C14-SB) was evaluated and it was observed that the deposition rate, morphology and micro-hardness of the deposits were enhanced by the addition of C14 -SB.
Abstract: 3-(N,N-Dimethyl myristyl-ammonio) propane sulfonate zwitterionic surfactant (C14-SB) which possessed both positive and negative charges was evaluated in the electroless Ni–P coating process. It was observed that the deposition rate, morphology and microhardness of the deposits were enhanced by the addition of C14-SB surfactant. The excess attractive forces from the negative head of C14-SB were strong enough to draw metallic nickel particles towards the substrate. Ni particles attempting to deposit on the electrolyte container were eliminated by the repulsive force from the positive head of the surfactant monomers. Thus, the deposition rate of the coating process was improved. The surfactant at its critical micelle concentration (CMC) doubles the deposition rate when compared to the substrate without surfactant. In addition, the microhardness of the deposit at the surfactant CMC increased by 62 %. The corrosion rate of the substrate without surfactant was 7.15 mpy, while it was 3.97 mpy for the substrate deposited with C14-SB zwitterionic surfactant at the CMC.

15 citations

Journal ArticleDOI
TL;DR: In this paper, the authors report on the improving nickel recovery efficiency of electroless Ni-P coating process and show that after adding 50% of excess amount of reducing agent at 30minutes of start of coating, the nickel recovery was significantly increased from 35% to 60.51%.

8 citations

Journal ArticleDOI
Peng Zhang1, Qiang Zhu1, Chuanjie Wang1, Heyong Qin, Gang Chen1 
TL;DR: In this article, the effects of rare earth on corrosion resistance of Ni-P coating were discussed and the results showed that Ce-sealed Ni-p coating possessed the excellent corrosion resistance.
Abstract: Nickel-based superalloys have been applied in many occasions due to perfect performance. The corrosion behaviors of such alloys always occur under actual service conditions, which seriously affect their normal service. In order to improve corrosion resistance of such alloys, Ce-sealed Ni-P coating was prepared. Ni-P coating and Ce-sealed Ni-P coating were compared through three-dimensional microscopic morphology and electrochemical measurements. The effects of rare earth on corrosion resistance of Ni-P coating were discussed. The results showed that Ce-sealed Ni-P coating possessed the excellent corrosion resistance. Ce-sealing in rare earth solution reduced the surface roughness of film layer, achieving a good sealing effect.

2 citations


Cites background from "Study on characterisation and influ..."

  • ...[10] Study on characterisation and influence of surfactants on adhesion and coating thickness of electroless Ni–P deposits....

    [...]

Journal ArticleDOI
TL;DR: In this article, an experimental work has been carried out to identify the impact and evaluation of various nano additives in Electroless Nickel-Phosphorous (EN-P) bath and different coatings were developed through EN-P bath on ASTM A106 B substrate influenced with nano additives.
Abstract: An experimental work has been carried out to identify the impact and evaluation of various Nano additives in Electroless Nickel-Phosphorous (EN-P) bath. Different coatings were developed through EN-P bath on ASTM A106 B substrate influenced with Nano additives. The bath consisted of Nickel Sulphate (26 g/L), Sodium Hypo-Phosphite (30 g/L) as the reducing agent, sodium acetate (16 g/L) as the stabiliser and Ammonium Hydrogen Di Fluoride (8 g/L) as the complexing agent. Nano additives such as ZnO, Al2O3 and CuO were added at various concentrations of 0.1%, 0.5%, 1%, and 2% in the EN-P bath and their influences on coating process characteristics were studied. The output parameters such as mechanical, characterisation and corrosion resistance evaluations were measured. The investigation proved that the suggested method resulted in substantial improvement on the quality of the coatings developed. The evaluation was reported at 1 % concentration of Nano additives in the bath. The overall performance of Nano Al2O3 in the En-P bath resulted in significant improvement on the corrosion resistance and quality of the coating produced as compared to other Nano additives.

Cites background from "Study on characterisation and influ..."

  • ...To enhance the coating efficiency and to reduce the escape of Nickel from the bath, addition of surfactants [31], [32] will improve the properties of the coatings...

    [...]