Topic
Electroless nickel plating
About: Electroless nickel plating is a(n) research topic. Over the lifetime, 1593 publication(s) have been published within this topic receiving 14940 citation(s).
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TL;DR: In this paper, a chemical conversion treatment and an electroless nickel plating were applied to AZ91D alloy to improve its corrosion resistance, which was verified by immersion test and potentiodynamic polarization test in 3.5 wt.% NaCl solution.
Abstract: A chemical conversion treatment and an electroless nickel plating were applied to AZ91D alloy to improve its corrosion resistance. By conversion treatment in alkaline stannate solution, the corrosion resistance of the alloy was improved to some extent as verified by immersion test and potentiodynamic polarization test in 3.5 wt.% NaCl solution at pH 7.0. X-ray diffraction patterns of the stannate treated AZ91D alloy showed the presence of MgSnO3 (.) H2O, and SEM images indicated a porous structure, which provided advantage for the adsorption during sensitisation treatment prior to electroless nickel plating. A nickel coating with high phosphorus content was successfully deposited on the chemical conversion coating pre-applied to AZ91D alloy. The presence of the conversion coating between the nickel coating and the substrate reduced the potential difference between them and enhanced the corrosion resistance of the alloy. An obvious passivation occurred for the nickel coating during anodic polarization in 3.5 wt.% NaCl solution. (C) 2003 Elsevier Ltd. All rights reserved.
286 citations
TL;DR: In this article, the effect of microstructure and plating parameters on AZ91D alloy was investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis.
Abstract: Electroless nickel-plating on AZ91D magnesium alloy has been investigated to understand the effect of substrate microstructure and plating parameters. The initial stage of the deposition was investigated using scanning electron microscopy (SEM) and energy dispersive X-ray analysis on substrates plated for a very short interval of time. The early stage of growth was strongly influenced by the substrate microstructure. Plating was initiated on b-phase grains probably due to the galvanic coupling of b and eutectic a-phase. Once the b-phase was covered with the coating, it then spread onto eutectic a and primary a-phase. The coating produced with the optimised bath showed 7 wt.% phosphorus with a hardness of approximately 600–700 VHN. The optimum ligand to metal ion ratio was found to be 1:1.5, while the safe domain for thiourea (TU) was in the range of 0.5–1 mgyl. Fluoride was found to be an essential component of the bath to plate AZ91D alloy with an optimum value of 7.5 gyl. The presence of 0.25–0.5 mgyl mercapto-benzo-thiosole (MBT) found to accelerate the plating process. 2003 Elsevier B.V. All rights reserved.
260 citations
Patent•
11 Apr 1979
TL;DR: In this article, a plated deposit in an electroless nickel plating bath containing an ester complex of a polyhydric acid or alcohol such as the diboron ester of glucoheptonic acid is described.
Abstract: Electroless, polymetallic nickel alloys containing an element of boron or phosphorus and one or more metals selected from tin, tungsten, molybdenum or copper which have unique properties and are produced as a plated deposit in an electroless nickel plating bath containing an ester complex of a polyhydric acid or alcohol such as the diboron ester of glucoheptonic acid.
187 citations
Patent•
17 Sep 1997
TL;DR: In this article, a high-build electroless gold plating method comprising the steps of immersing a workpiece in the electroless nickel plating bath, thereby chemically depositing a nickel coating on the workpiece, and then inserting the nickel-plated workpiece into an electroless girding bath, where the gold coating was chemically deposited.
Abstract: To an electroless nickel plating solution comprising a water-soluble nickel salt, a reducing agent, and a complexing agent is added a polythionate or dithionite. The invention also provides a high-build electroless gold plating method comprising the steps of immersing a workpiece in the electroless nickel plating bath, thereby chemically depositing a nickel coating on the workpiece, and immersing the nickel-plated workpiece in an electroless gold plating bath, thereby chemically depositing a gold coating on the workpiece.
181 citations