Ebadpour R

Bio: Ebadpour R is an academic researcher. The author has contributed to research in topics: Corrosion & Coating. The author has an hindex of 1, co-authored 1 publications receiving 13 citations.

Effect of cobalt content on wear and corrosion behaviors of electrodeposited Ni-Co/WC nano-composite coatings.

Abstract: Metal-ceramic composite coatings are widely used in automotive and aerospace industries as well as micro-electronic systems. Electrodeposition is an economic method for application of these coatings. In this research, nickel-cobalt coatings reinforced by nano WC particles were applied on carbon steel substrate by pulse electrodeposition from modified Watts bath containing different amounts of cobalt sulphate as an additive. Saccharin and sodium dodecyl sulphate (SDS) were also added to electroplating bath as grain refiner and surfactant, respectively. The effect of cobalt content on wear and corrosion behavior of the coatings was investigated. Wear and corrosion properties were assessed by pin-on-disk and potentiodynamic polarization methods, respectively. Phase analysis was performed by X-ray diffraction (XRD) using CuK(alpha) radiation and the worn surfaces were studied by means of Scanning Electron Microscopy (SEM). The results showed that the addition of cobalt improved the wear resistance of the coatings. In the presence of 18 g/L cobalt in electrodeposition bath, the wear rate of the coating decreased to 0.002 mg/m and the coefficient of friction reduced to 0.695 while they were 0.004 mg/m and 0.77 in the absence of cobalt, respectively. This improvement in wear properties can be attributed to the formation of hcp phase in metallic matrix. Meanwhile, the corrosion resistance of the coatings slightly reduced because cobalt is more active metal with respect to nickel.

A review of electrodeposited Ni-Co alloy and composite coatings: Microstructure, properties and applications

Abstract: Ni Co alloy electrodeposits have been widely employed in industry due to their good corrosion and wear resistance, high mechanical strength, moderate thermal conductivity and outstanding electrocatalytic and magnetic properties. This review aims to provide an insight into the mechanism of electrodeposition and effect of operational parameters and deposit microstructure, together with the mechanical, electrochemical and tribological characteristics of Ni Co alloys and included particle, composite deposits. Potential applications of the coatings have also been considered in applications as diverse as additive manufacturing, micro-tools, micro-sensors, electronic imaging and electrochemical energy conversion.

Robust Ni/WC superhydrophobic surfaces by electrodeposition

Abstract: Superhydrophobic, water repellent surfaces have attracted much attention but poor surface mechanical properties have limited their wider practical application. Robust surfaces based on nickel–tungsten carbide composite coatings have been electrodeposited. The surfaces showed superhydrophobicity after being modified by stearic acid. The maximum contact angle of water was 164.3 degrees with a sliding angle close to zero. By controlling the deposition conditions, versatile coatings have been produced and the effects of morphology on wettability are discussed. Coating texture has been analyzed by X-ray diffraction. The surfaces showed excellent abrasion resistance and water-repellence.

Evaluation of TiO2 Nanoparticles Concentration and Applied Current Density Role in Determination of Microstructural, Mechanical, and Corrosion Properties of Ni–Co Alloy Coatings

Abstract: The goal of the present investigation is to evaluate the influences of plating parameters such as TiO2 nanoparticles concentration in the plating bath and applied current density on the microstructure-related and mechanical properties as well as corrosion behavior of Ni–Co coatings. The coatings were fabricated by different current densities and TiO2 nanoparticles concentration over the range 2–8 A dm–2 and 0–30 g/L, respectively. Results demonstrate that the incorporation of TiO2 nanoparticles into the plating bath coupled with the change in current density can deeply affect the microstructure-related, mechanical properties as well as corrosion resistance of Ni–Co coatings. According to the results, Ni–Co–20 g/L TiO2 coatings electroplated at current density of 4 A dm–2 shows the superior properties. The synergistic effects of higher Co amount coupled with the higher volume fraction of TiO2 throughout the microstructure of the coating is responsible for the above-mentioned improvements.

Recent Progress in Precision Machining and Surface Finishing of Tungsten Carbide Hard Composite Coatings

Abstract: Owing to their high hardness, fracture toughness and oxidation resistance, tungsten carbide (WC) coatings are extensively deposited on parts that operate in demanding applications, necessitating wear, erosion, and corrosion resistance. The application of thick and hard WC coatings has an inevitable effect on the original dimensions of the parts, affecting the geometrical tolerances and surface roughness. The capability of achieving a sub-micron surface finish and adhere to tight geometrical tolerances accurately and repeatably is an important requirement, particularly with components that operate in high-precision sliding motion. Meeting such requirements through conventional surface finishing methods, however, can be challenging due to the superior mechanical and tribological properties of WC coatings. A brief review into the synthesis techniques of cemented and binderless WC coatings is presented together with a comprehensive review into the available techniques which are used to surface finish WC-based coatings with reference to their fundamental mechanisms and capabilities to process parts with intricate and internal features. The binderless WC/W coating considered in this work is deposited through chemical vapour deposition (CVD) and unlike traditional cemented carbide coatings, it has a homogenous coating structure. This distinctive characteristic has the potential of eliminating key issues commonly encountered with machining and finishing of WC-based coatings. Here, six contact and non-contact surface finishing techniques, include diamond turning, precision grinding, superfinishing, vibratory polishing, electrical discharge machining, and electropolishing are discussed along with their current use in industry and limitations. Key challenges in the field are highlighted and potential directions for future investigation, particularly on binderless WC coatings, are proposed herein.