Effects of pH and Current Density on Microstructure and Hardness of the Cobalt-Tungsten Coating.
Abstract
In this study, cobalt-tungsten coatings were electrodeposited on copper substrates. Nanocrystalline and amorphous cobalt tungsten alloys were electrodeposited from citrate-boric acid baths. The characterization of the alloy coatings was carried out by scanning electron microscopy (SEM), X-ray fluorescence (XRF), and X-ray diffraction (XRD). The most significant factors, such as current density and pH of the electrolyte that affect the morphology, tungsten composition, and microhardness value, were studied. The tungsten content of the electrodeposits varied 11 to 46% by changing process variables. The microhardness value of the coatings was decreased dramatically when the tungsten composition exceeded 35%. Response surface methodology was used to construct models for predicting microhardness value and tungsten composition of the coating. The optimal conditions for the electrodeposition were found as follows: current density of 5A/dm2 and pH 6. Under optimal conditions, the coating exhibits a hardness of 570 HV.
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- Su YH, Kuo TC, Lee WH et al. Effect of tungsten incorporation in cobalt tungsten alloys as seedless diffusion barrier materials. Microelectronic Engineering 2017; 171: 25–30.
- Fu T, Cui K, Zhang Y et al. Oxidation protection of tungsten alloys for nuclear fusion applications: A comprehensive review. J Alloys Compd 2021; 884: 161057.
- Belevskii SS, Gotelyak A V, Yushchenko SP, Dikusar AI. Electrodeposition of Nanocrystalline Fe − W Coatings from a Citrate Bath. Surface Engineering and Applied Electrochemistry 2019; 55: 119–129.
- Costa JM, Porto MB, Amancio RJ, de Almeida Neto AF. Effects of tungsten and cobalt concentration on microstructure and anticorrosive property of cobalt-tungsten alloys. Surfaces and Interfaces 2020; 20.
- Wei GY, Lou JW, Ge HL et al. Co-W films prepared from electroplating baths with different complexing agents. Surface Engineering 2012; 28: 412–417.
- Vernickaite E, Tsyntsaru N, Sobczak K, Cesiulis H. Electrodeposited tungsten-rich Ni-W, Co-W and Fe-W cathodes for efficient hydrogen evolution in alkaline medium. Electrochimica Acta 2019; 318: 597–606.
- Fathollahzade N, Raeissi K. Electrochemical evaluation of corrosion and tribocorrosion behaviour of amorphous and nanocrystalline cobalt-tungsten electrodeposited coatings. Materials Chemistry Physics 2014; 148: 67–76.
- Dadvand N, Jarjoura G, Kipouros GJ. Electrodeposition of cobalt-tungsten alloys from alkaline citrate containing bath as alternative for chromium hexavalent replacement. Canadian Metallurgical Quarterly 2013; 52: 391–397.
- Vernickaite E, Cesiulis H, Tsyntsaru N. Evaluation of corrosion and tribological behavior of electrodeposited tungsten alloys. Proc 9th Int Sci Conf BALTTRIB 2017 - Dedic to 100th Anniv Restit Lith 2018; 207–214.
- Belevskii SS, Bobanova JI, Buravets VA et al. The influence of gluconate bath parameters on the rate of electrodeposition and mechanical properties of Co–W coatings. Proc 9th Int Sci Conf BALTTRIB 2017 - Dedic to 100th Anniv Restit Lith 2018; 7–12.