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1 – 10 of 59
Article
Publication date: 24 August 2023

Haijing Sun, Jianing Cui, He Wang, Shuai Yang, Souavang Xaikoua, Yong Tan, Xin Zhou, Baojie Wang and Jie Sun

The purpose of this paper is to study the effect of temperature on Zn–Ni alloys in ChCl–Urea.

Abstract

Purpose

The purpose of this paper is to study the effect of temperature on Zn–Ni alloys in ChCl–Urea.

Design/methodology/approach

Based on cyclic voltammetry experiments, the deposition behavior and kinetics of the Zn–Ni alloy are studied. The nucleation process of the Zn–Ni alloy is studied in detail via chronoamperometry experiments. The effects of the deposition temperature on the microstructure, Ni content and phase composition of Zn–Ni alloy coatings are investigated via scanning electron microscopy and X-ray diffraction (XRD) combined with classical thermodynamics.

Findings

The results show that with increasing temperature, the reduction peak shifts toward a more positive electric potential, which is beneficial for the co-electric deposition process, and the diffusion coefficient is estimated. With increasing temperature, the nucleation process of the Zn–Ni alloy becomes a three-dimensional instantaneous nucleation, the typical kinetic parameters are determined using the standard 3D growth proliferation control model and the Gibbs free energy is estimated. The Zn–Ni alloy coatings are prepared via normal co-deposition. With increasing temperature, the degree of crystallinity increases, the coating gradually becomes uniform and compact and the XRD peak intensity increases.

Originality/value

The nucleation process of the Zn–Ni alloy at different temperatures is analyzed. The diffusion coefficient D and Gibbs free energy are calculated. The contribution of the three processes at different temperatures is analyzed. The effect of temperature on the morphology of the Zn–Ni alloy coatings is studied.

Details

Anti-Corrosion Methods and Materials, vol. 70 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 20 February 2014

K. Sharma and A. Seethagirisha

The mechanical properties like hardness, tensile strength, wear resistance of electro-co-deposited Ni-SiC coatings are dependent on factors like bath temperature, current density…

Abstract

The mechanical properties like hardness, tensile strength, wear resistance of electro-co-deposited Ni-SiC coatings are dependent on factors like bath temperature, current density, duration of deposition, amount of SiC particles etc. Ni-SiC nano composite coatings were prepared on a mild steel substrate by electro-co-deposition process. In this study, the effect of electrochemical bath parameters such as bath temperature, current density and SiC loading were varied and effect of this variation on the coating thickness and tensile strength of Ni-SiC composite coating was studied. The experimental results showed that, a uniform deposit thickness was obtained for 3 A/dm2 current density, temperature of 55°C and loading of 4 g/l. A peak value of coating thickness was observed at a current density of 4 A/dm2 from the experiment. The experimental results also showed that, the tensile strength of the composite coating containing SiC the is significantly higher than pure Ni coating and the tensile strength increases with an increase in the percentage of SiC particles in Ni-SiC coatings. The tensile strength of the composite coating increased by nearly about 52% with increasing SiC loading and then decreased.

Details

World Journal of Engineering, vol. 10 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 1 January 1984

George E.F. Brewer

During the 1960s, a new paint application process began to appear, variously called “Electro‐coating”, “Electropainting”, “Electrophoretic deposition”, etc. The process extends…

Abstract

During the 1960s, a new paint application process began to appear, variously called “Electro‐coating”, “Electropainting”, “Electrophoretic deposition”, etc. The process extends and modifies the principles of electroplating into the field of electro‐deposition of paint. It is best characterised as the utilisation of Electrodepositable Synthetic Filmforming Macro‐ions. The process, like electroplating, consists in submerging objects to be coated in a bath of waterdispersed ions. These, through the action of an impressed DC current, are deposited on the electrode of opposite polarity. While metal ions require 1 Faraday for the deposition of approximately 30g metal, electrocoating of paints requires 1 Faraday for typically 1,600g of paint.

Details

Pigment & Resin Technology, vol. 13 no. 1
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 18 January 2008

S. Yang, M.M. Mohebi and J.R.G. Evans

The purpose of this paper is to present a new powder‐based solid freeforming method based on conventional furnace sintering after co‐deposition of mould and part powder materials.

Abstract

Purpose

The purpose of this paper is to present a new powder‐based solid freeforming method based on conventional furnace sintering after co‐deposition of mould and part powder materials.

Design/methodology/approach

Based on acoustic powder deposition, both mould and part powder materials are delivered simultaneously into the forming area according to the cross section of the 3D computer file. The part is formed in the form of loose powder surrounded by the mould powder again in a loose state. The whole assembly can then be sintered by a conventional method and the mould powder, which has a higher sintering temperature than that of part powder, remains in the loose state after sintering and can be removed.

Findings

Complex‐shaped components containing re‐entrant cavities and the capability of being made with 3D functional gradients can be rendered directly as a powder preform suitable for subsequent compaction or direct sintering in a conventional furnace. The flowability and compatibility of the powders need to be selected carefully and the track distance between part/mould powders is important for forming a vertical wall.

Research limitations/implications

The main factors affecting building from powder tracks are identified, including the effect of track distance at an interface on integrity, discontinuous feeding on bends and the effects of fill strategies. The flow rates of the part and mould powder as well as their geometrical maps are controlled computationally. Materials and instrumental aspects are discussed.

Originality/value

This paper describes a method to produce complex‐shaped object without residual stress and expensive lasers and the process could be modified to include 3D functional gradients.

Details

Rapid Prototyping Journal, vol. 14 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 27 May 2014

Mohsen Salehi Doolabi, Sayed Khatiboleslam Sadrnezhaad and Davood Salehi Doolabi

– The main aim of this study was to improve current efficiency and to obtain thicker coatings via aluminum oxide (Al2O3) addition to the chromium (Cr) (III) bath.

Abstract

Purpose

The main aim of this study was to improve current efficiency and to obtain thicker coatings via aluminum oxide (Al2O3) addition to the chromium (Cr) (III) bath.

Design/methodology/approach

Pure Cr and nanocomposite Cr–Al2O3 coatings were electrodeposited from Cr (III) bath onto cathode copper substrates by conventional method. Dependence of current efficiency to current density, Al2O3 content and particle size were investigated.

Findings

Current efficiency increased with Al2O3 amount and decreased with Al2O3 particle size. Maximum current efficiency was achieved at 25 A/dm2 for pure Cr and 30 A/dm2 for composite coatings. Al2O3 bath content, current density and stirring rate increased the coating Al2O3 weight per cent significantly. Addition of Al3+ bath composition inhibited nanoparticle agglomeration, increasing film homogeneity. Cr–Al2O3 nanocomposites showed higher microhardness and better corrosion resistance than pure Cr layer.

Originality/value

Cr (III) is not as toxic and as carcinogenic as Cr (VI) which is widely used for Cr electroplating these days. Low current efficiency and poor product quality are, however, major drawbacks of the former. This paper describes significant improvements obtainable by addition of Al2O3 nanoparticles to the Cr (III) bath for increasing the microhardness, the corrosion resistance and the current efficiency of the deposition.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 August 2001

Z. Abdel Hamid

Zinc‐cobalt alloys have been electrodeposited from a sulphate bath. The effect of process variables, including temperature, time, concentration of cobalt sulfate and current…

Abstract

Zinc‐cobalt alloys have been electrodeposited from a sulphate bath. The effect of process variables, including temperature, time, concentration of cobalt sulfate and current density on the Zn‐Co deposition was investigated from kinetic and mechanistic viewpoints. Activation energies, enthalpies and entropies were determined according to Arrhenius and absolute rate theories. The codeposition mechanism of TiO2 with cobalt‐zinc in the presence of benzyl triethanol ammonium exthoxylate (BTAE) has been studied. The optimum concentration of the additive was reported. The mechanism of incorporation of TiO2 was suggested and confirmed in view of calculated free energy of adsorption of TiO2. Corrosion resistance of Zn‐Co‐TiO2 alloy was determined by a salt spray test under most of the plating conditions studied.

Details

Anti-Corrosion Methods and Materials, vol. 48 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 June 1997

Saher Shawki and Z. Abdel Hamid

Electrodeposited Ni‐P composite coatings incorporating a variety of inorganic particles were obtained from Watt’s nickel bath containing sodium hypophosphite. The mechanism of…

Abstract

Electrodeposited Ni‐P composite coatings incorporating a variety of inorganic particles were obtained from Watt’s nickel bath containing sodium hypophosphite. The mechanism of co‐deposition of various particles (SiC, Al2O3, quartz and sand) was studied in view of the electro‐kinetic charge characterizing the solid particles. Means to improve the mobility of the particles in the plating solution were investigated using sodium oleate as surface active agent. The purpose was to increase particle content in the coating to attain high hardness values. Special attention was given to the deposition process using SiC particles. The surface morphology, hardness and wear resistance of the composite coatings were determined. Hardness values were maximized by simple heat treatment in air atmosphere which led to the precipitation of the hard Ni3P phase. Sound, coherent and high wear resistance coatings could be produced.

Details

Anti-Corrosion Methods and Materials, vol. 44 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 May 2019

Victor Sunday Aigbodion, Enyi C.C., Akinlabi E.T., Suleiman I.Y., Ezema I.C. and Mgbemene C.A.

This paper aims to investigate the parametric study of addition of snail shell particles (SSp) and bath temperature on the properties of Zn-ZnO-SSp composites coating.

Abstract

Purpose

This paper aims to investigate the parametric study of addition of snail shell particles (SSp) and bath temperature on the properties of Zn-ZnO-SSp composites coating.

Design/methodology/approach

Bath temperatures of 60°C and 90°C and SSp of 0, 5, 10, 15, 20 and 25g were used in the electrodeposition. The microstructure, electrochemical, wear and hardness values of the coated samples were determined.

Findings

Highest coating thickness of 240 µm, 277 per cent improvement in hardness values, 66.67 per cent improvement of wear rate were obtained at bath temperature of 60oC and 15gSSp addition over that of the uncoated sample. There was improvement in corrosion resistance after composites coating. Maximum improvement in the properties was obtained at bath temperature of 60°C at 15gSSp addition.

Originality/value

It has been established in this work that bath treatment and SSps improved the properties of the developed coating.

Details

World Journal of Engineering, vol. 16 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 5 April 2013

Yingxin Goh, A.S.M.A. Haseeb and Mohd Faizul Mohd Sabri

The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)‐free solder alloys, so that new studies can be carried out to solve…

1299

Abstract

Purpose

The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)‐free solder alloys, so that new studies can be carried out to solve processing issues.

Design/methodology/approach

The paper reviews the available reports on the electrodeposition of tin (Sn)‐based solder systems and identifies the challenges in this area.

Findings

Compositional control remains a major challenge in this area, where the achievement of desired composition for binary and ternary alloys is subjected to uncertainties. The use of chelating agents in the bath and optimization of parameters can assist the achievement of near‐desired alloy composition. Acidic plating baths are preferred due to their compatibility with photoresists but oxidation of stannous ions causes poor bath stability. Antioxidants, reducing agents and low oxygen overpotential anodes can suppress the oxidation rate and increase the lifespan of plating baths. Apart from chelating agents and antioxidants, various categories of additives can be added to improve quality of deposits. Surfactants, grain refiners and brighteners are routinely used to obtain smooth, fine‐grained and bright deposits with good thermo‐mechanical properties.

Originality/value

The paper provides information on the key issues in electrodeposition of Pb‐free solder alloys. Possible measures to alleviate the issues are suggested so that the electrodeposition technique can be established for mass production of a wider range of solder alloys.

Details

Soldering & Surface Mount Technology, vol. 25 no. 2
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 1 March 1989

M.R. Kalantary, S.A. Amadi and D.R. Gabe

A study has been carried out employing a vibratory motor, offering amplitudes of 0·4–4 mm at 50 Hz in acid copper sulphate as a model electrolyte in which α‐Al2O3 particles are…

Abstract

A study has been carried out employing a vibratory motor, offering amplitudes of 0·4–4 mm at 50 Hz in acid copper sulphate as a model electrolyte in which α‐Al2O3 particles are suspended for co‐deposition, yielding a composite electrodeposit. Using a horizontal disc vibrator at the bottom of the container, perforated discs have been shown to give superior agitation and a laminar/turbulent transition has been identified. Incorporation of particles is a maximum at the transition. In the laminar regime Sh‐Re0·037 and in the turbulent regime Sh‐Re0·82. Mass transport enhancement was measured for a variety of disc and tank diameters and enhancement factors for electrodeposition of 3–40 times were obtained. In these circumstances a modified Reynolds number Re1 was employed Re1 = 100 ad2(d1−d2)/υd2 and, assuming a conventional dependence upon Sc, a full correlation of the type Sh1 = constant Re1a Sc0·33 was obtained where the constant took values of 10–40 and ‘a’ took values of 0·83–1·1 depending upon precise location within the tank of the mass transfer probe.

Details

Circuit World, vol. 15 no. 4
Type: Research Article
ISSN: 0305-6120

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