pH ve Akım Yoğunluğunun Kobalt-Tungsten Kaplamalarının Mikroyapı ve Sertliğine Etkileri

Bu çalışmada, bakır altlık malzemeler kullanılarak kobalt tungsten kaplamalar üretilmiştir. Sitrat-borat banyosu kullanılarak yapılan çalışmalarda, nanokristalin ve amorf kobalt-tungsten kaplamalar üretilmiştir. Kaplamaların karakterizasyonu için taramalı elektron mikroskobu (SEM), X-ışını floresansı (XRF) ve X-ışını kırınımı (XRD) cihazları kullanılmıştır. pH ve akım yoğunluğunun, kaplama morfolojisine, tungsten bileşimine ve mikrosertlik değerine etkileri incelenmiştir. Çalışmalar sırasında proses değişkenleri değiştirilerek üretilen numunelerin tungsten içeriği %11 ile 46 arasında değişmiştir. Deneylerde en yüksek sertlik değeri olarak 570 HV ölçülmüştür. Elektrolit pH’ı 6 olarak seçilen bu deneyde uygulanan akım yoğunluğu ise 5A/dm2’dir. Kaplamaların tungsten içeriğinin %35’i geçmesi ile kaplamaların sertliklerinde düşüş gözlemlenmiştir. Cevap yüzey yöntemi kullanılarak kaplamanın mikrosertlik değeri ve tungsten bileşimini tahmin edebilecek matematiksel modeller oluşturulmuştur

Anahtar Kelimeler:

kobalt, tungsten, elektrokaplama

Effects of pH and Current Density on Microstructure and Hardness of the Cobalt-Tungsten Coating.

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.

Keywords:

cobalt, tungsten, electrodeposition,

PDF

___

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.
Weston DP, Harris SJ, Capel H et al. Nanostructured Co-W coatings produced by electrodeposition to replace hard Cr on aerospace components. The International Journal of Surface Engineering and Coatings 2010; 88: 47–56.
Frank AC, Sumodjo PTA. Electrodeposition of cobalt from citrate containing baths. Electrochim Acta 2014; 132: 75–82.
Tsyntsaru N, Cesiulis H, Budreika A et al. The effect of electrodeposition conditions and post-annealing on nanostructure of Co-W coatings. Surface Coatings Technology 2012; 206: 4262–4269.
Bodaghi A, Hosseini J. Corrosion behavior of electrodeposited cobalt-tungsten alloy coatings in NaCl aqueous solution. International Journal of Electrochemical Science 2012; 7: 2584–2595.
Frank AC, Sumodjo PTA. Electrodeposition of cobalt from citrate containing baths. Electrochimica Acta 2014; 132: 75–82.
Tsyntsaru N, Cesiulis H, Donten M et al. Modern trends in tungsten alloys electrodeposition with iron group metals. Surface Engineering Applied Electrochemistry 2012; 48: 491–520.
Oskay KO, Demirel B. Research Article Optimizing the composition of electroplated composite coating NiCrAl. Acta Physica Polonica A 2018; 36: 801–808.
Ma L, Xi X, Nie Z, Dong T, Mao Y. Electrodeposition and characterization of Co-W Alloy from regenerated Tungsten salt. Int J Electrochem Sci 2017; 12: 1034–1051.
Costa JD, de Sousa MB, Alves JJN et al. Effect of electrochemical bath composition on the preparation of Ni-W-Fe-P amorphous alloy. International Journal of Electrochemical Science 2018; 13: 2969–2985.
Vernickaite E, Tsyntsaru N, Cesiulis H. Electrodeposited Co-W alloys and their prospects as effective anode for methanol oxidation in acidic media. Surface Coatings Technology 2016; 307: 1322–1328.
Nicolenco A, Tsyntsaru N, Fornell J et al. Mapping of magnetic and mechanical properties of Fe-W alloys electrodeposited from Fe(III)-based glycolate-citrate bath. Mater Des 2018; 139: 429–438.
Vernickaite E, Tsyntsaru N, Cesiulis H. Electrodeposition and corrosion behaviour of nanostructured cobalt–tungsten alloys coatings. Trans Inst Met Finish 2016; 94: 313–321.
Rupert TJ, Schuh CA. Sliding wear of nanocrystalline Ni-W: Structural evolution and the apparent breakdown of Archard scaling. Acta Material 2010; 58: 4137–4148.
Sriraman KR, Ganesh Sundara Raman S, Seshadri SK. Corrosion behaviour of electrodeposited nanocrystalline Ni-W and Ni-Fe-W alloys. Materials Science Engineering A 2007; 460–461: 39–45.
Atanassov N, Gencheva K, Bratoeva M. Properties of Nickel-Tungsten Alloys Electrodeposited from Sulfamate Electrolyte. Plat Surf Finish 1997; 84: 67–71.
Wasekar NP, Hebalkar N, Jyothirmayi A Influence of pulse parameters on the mechanical properties and electrochemical corrosion behavior of electrodeposited Ni-W alloy coatings with high tungsten content. Corrosion Science 2020; 165: 108409.
Sriraman KR, Sundara Raman SG, Seshadri SK. Synthesis and evaluation of hardness and sliding wear resistance of electrodeposited nanocrystalline Ni-W alloys. Materials Science Engineering A 2006; 418: 303–311.