scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Preparation of electroless Ni–P composite coatings containing nano-scattered alumina in presence of polymeric surfactant

01 Aug 2012-Progress in Natural Science: Materials International (Elsevier)-Vol. 22, Iss: 4, pp 318-325
TL;DR: In this article, the dispersion stability of alumina colloidal particles stabilized by polymeric (non-ionic) surfactants in an electroless bath was investigated and the surface morphology and the relevant structure were evaluated by scanning electron microscopy and X-ray diffraction.
About: This article is published in Progress in Natural Science: Materials International.The article was published on 2012-08-01 and is currently open access. It has received 51 citations till now. The article focuses on the topics: Coating & Corrosion.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, Tungsten trioxide (WO3) nanoparticles were loaded into the electroless Ni-P bath in order to synthesize the NiP/nano-WO 3 coatings, which were verified by Energy Dispersive X-ray Spectroscopy (EDS) technique.

44 citations

Journal ArticleDOI
TL;DR: In this paper, Ni-P-nano-Al2O3 composite coatings on mild steel were obtained by adding Al 2O3 nanoparticles into the traditional electroless NiP bath.
Abstract: Ni-P-nano-Al2O3 composite coatings on the mild steel were obtained by adding Al2O3 nanoparticles into the traditional electroless Ni-P bath. Cationic and anionic surfactants were used to prevent the agglomeration of the incorporated nano-Al2O3. Surface morphology, compositions and microstructures of the coating were studied using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and X-ray diffraction (XRD) as well. Corrosion resistances of the modified mild steel samples were evaluated in 3.5 wt.% NaCl solution by electrochemical impedance spectroscopy (EIS). The results showed that compared to the pure Ni-P coating on the mild steel, the coating formed in the bath with 6 g/L nano-Al2O3 performed the highest resistance. Under the optimal conditions, the adding of anionic surfactant (SDBS) improved the anti-corrosion performance of the samples further, while the addition of cationic surfactant led to a worse corrosion resistance. The potential mechanism was that anionic surfactant molecules would contact with active sites of Ni-P composite coating and nano-Al2O3 in the bath, which would improve the dispersion of nano-Al2O3, thus leading to a homogeneous coating with better corrosion resistance.

39 citations

Journal ArticleDOI
TL;DR: In this paper, different types of surfactants (cationic, anionic, and polymeric) were added to the plating bath to enhance the incorporation of nano-sized TiC particles into electroless Ni-P (EN) coating.

39 citations

Journal ArticleDOI
TL;DR: In this article, the phase structure characterization of Ni-B-Sn nano-coating was investigated using X-ray diffraction (XRD) and the crystal size was calculated using Scherrer's equation, which revealed that the addition of tin particle and heat treatment provides satisfactory enhancement in hardness and wear resistance of the coatings.

37 citations

Journal ArticleDOI
TL;DR: In this paper, simple and non-toxic oxalate pretreatment was used for electroless Ni-P plating on AM60B magnesium alloy, and the morphology, chemical composition, microstructure, and corrosion resistance were investigated by the SEM, Energy Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD), and electrochemical methods, respectively.
Abstract: In this work, simple and non-toxic oxalate pretreatment was used for electroless Ni–P plating on AM60B magnesium alloy. The morphology and chemical composition of the alloy sample after oxalate pretreatment were studied by X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM), respectively. Also, the morphology, chemical composition, microstructure, and corrosion resistance of the electroless Ni–P coatings were investigated by the SEM, Energy Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD) and electrochemical methods, respectively. Moreover, porosity and adherence of the applied electroless coatings were examined by porosity and thermal sock tests, respectively. The SEM images revealed that the alloy surface was covered by a cracked conversion film and the cracks were extended by increasing the immersion time from 5 to 30 min. The XPS analysis showed that the conversion layer was mainly composed of the magnesium oxalate with nodular molybdenum oxide particles on the β phase area due to the presence of the sodium molybdate in the pretreatment solution as an accelerator. The formation of the nickel nucleation centers has been started through the cracks of the oxalate film. Also, cauliflower-like nodular electroless Ni–P coatings were formed on the surface of the 5, 15, and 30 min oxalate treated samples after 3 h plating and the surface smoothness of the coatings decreased by increasing the pretreatment time. The EDX analysis showed that the coatings have moderate phosphorus (P) content which slightly increases with pretreatment time. Moreover, the XRD patterns revealed that all of the electroless coatings have mixed crystalline amorphous structure. Application of the electroless Ni–P coating was significantly increased the corrosion resistance of the bare alloy and the best corrosion protection performance was observed for the 15 min pretreated sample. All of the applied coatings were pore-free and adherent to the alloy substrate. The micro-hardness value of the AM60B alloy sample was significantly increased after application of the electroless coatings.

33 citations

References
More filters
Journal ArticleDOI
TL;DR: In this paper, the effects of continuous heating on the crystallisation kinetics and phase transformation behavior of electroless nickel-phosphorus deposits plated on mild steel substrates, with high phosphorus contents of 12 and 16 wt, were studied.

205 citations

Journal ArticleDOI
TL;DR: In this paper, high phosphorus electroless nickel bath has been used to prepare composite coatings containing alumina powders (50 nm, 0.3 μm and 1.0 μm).
Abstract: High phosphorus electroless nickel bath has been used to prepare composite coatings containing alumina powders (50 nm, 0.3 μm and 1.0 μm). Deposits were characterized for its structure, morphology and hardness. Incorporation of particle has a marginal influence on the composition. More amount of particle incorporation and uniform distribution was found in composite coatings obtained with 1.0-μm (C3) alumina particles compared to 50-nm (C1) and 0.3-μm (C2) alumina particles. XRD results showed a broad peak of nickel and low intensity alumina peaks present in C3 composite coating in as-plated condition. A marginal improvement in hardness was noticed in as-plated composite coatings. A 15% increase in microhardness was observed in the heat-treated (400 °C for 1 h) composite coatings. Potentiodynamic polarization measurements made on these deposits in 3.5% sodium chloride solution showed that uniform corrosion occurred in C1 and C2 composite coatings whereas localized corrosion was observed in C3 composite coating.

168 citations

Journal ArticleDOI
15 Mar 2007-Wear
TL;DR: In this article, hardness and wear resistance of two types of electroless coating have been investigated including Ni-P and Ni−P-Al 2 O 3 coatings, which were applied on AISI 1045 steel discs by electroless deposition process and then they were heat treated at 200, 400 and 600°C for 1h.

164 citations

Journal ArticleDOI
TL;DR: In this paper, the formation of electroless Ni-P graded coatings, with varying nickel and phosphorus contents of the individual layers and to evaluate their corrosion resistance by polarization and electrochemical impedance spectroscopic studies, was studied.
Abstract: Electroless Ni–P coatings provide high hardness and excellent resistance to wear and abrasion The present work aims to study the formation of electroless Ni–P graded coatings, with varying nickel and phosphorus contents of the individual layers and to evaluate their corrosion resistance by polarization and electrochemical impedance spectroscopic studies The possibility of preparing electroless Ni–P graded coatings by sequential immersion in three different plating baths is discussed The study reveals that electroless Ni–P graded coatings offer better corrosion resistance than non-graded Ni–P coatings

157 citations

Journal ArticleDOI
TL;DR: In this article, the amount of SiO 2 nano-particles co-deposited in the Ni-P matrix was around 2.5 to 8.5% phosphorus and the X-ray diffraction (XRD) pattern of Ni−P/nano-SiO 2 coating was very similar to that of plain electroless Ni·P coating, whose structure was also amorphous.

130 citations


"Preparation of electroless Ni–P com..." refers background in this paper

  • ...Newly developed Ni–P composite coatings with particles like Al2O3 [3–8], SiC [9–12], diamond [13], SiO2 [14] and Si3N4 [15] have shown to improve corrosion and abrasion properties....

    [...]

  • ...P composite coatings with particles like Al2O3 [3–8], SiC [9–12], diamond [13], SiO2 [14] and Si3N4 [15] have shown to improve corrosion and abrasion properties....

    [...]