Nikel-Kobalt (Ni-Co) Alaşımlı Kaplamalarda Co Miktarının Mikroyapıya Etkisi

Bu çalışmada, Ni-Co alaşımlı kaplamalar elektrolitik yöntemle çelik malzeme yüzeyine sülfat banyosundan bir güç kaynağı yardımıyla hazırlanmıştır. Elektrolit içinde Co miktarındaki değişimin kaplamanın kompozisyon, faz yapısı ve morfoloji üzerine etkileri incelenmiştir. Elde edilen kaplamalar; X‑ışını kırınım cihazı (XRD) ve taramalı elektron mikroskobu (SEM) ile karakterize edilmişlerdir. Sonuçlara göre, elektrolit içindeki farklı Co konsantrasyonu Ni-Co alaşımlı kaplama tabakasının özelliklerine etki etmektedir. Elektrolitteki Co oranının artışı ile birlikte alaşımlı kaplama tabakasında depozitlenen Co oranında ciddi bir artış söz konusudur. Ni-Co alaşımlı kaplama tabakasında YMK+HSP kristal yapısı artan Co miktarı ile HSP yapıya dönüşmektedir. Aynı zamanda alaşımlı kaplama tabakasındaki Co oranındaki artış ile birlikte yüzey morfolojisinde değişim gözlemlenmiştir ve daha granüler bir yapı oluşmuştur.

Anahtar Kelimeler:

Elektrolit, Ni-Co alaşımı, XRD, Yüzey morfolojisi

The Effect of Co Content on The Microstructure of Nickel-Cobalt (Ni-Co) Alloy Coatings

In this study, Ni-Co alloy coatings were prepared on the steel substrates with electrodeposition method from a sulphate baths using power supply. The effect of Co content in electrolyte on the composition, phase structure and surface morphology of alloy coating were investigated. The prepared coatings were characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). According to the results, Co concentration in the electrolyte affects the properties of the Ni-Co alloy coating layer. There is a serious increase of Co content deposited Ni-Co alloy coating when the Co concentration is increased in the electrolyte. The both FCC and HCP crystal structures of Ni-Co alloy coating layer began to transformin into HCP structure with increasing amount of Co content. At the same time, a change in the surface morphology was observed with an increase in Co ratio in the alloy coating layer and a more granular structure was formed.

Keywords:

Electrolyte, Ni-Co alloy, XRD, Surface morphology,

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Atuanya, C.U. ve Ekweghiariri, D.I., 2017. Experimental correlation between varying processing properties and wear behaviour of ternary Ni-Co-SiO2 composites coating of mild steel, The International Journal of Advanced Manufacturing Technology, 88 (9-12), 2581–2588.
Bai, A. ve Hu, C.C., 2002. Effects of electroplating variables on the composition and morphology of nickel–cobalt deposits plated through means of cyclic voltammetry, Electrochimica acta, 47 (21), 3447-3456.
Bakhit, B. ve Akbari, A., 2013. Nanocrystalline Ni–Co alloy coatings: electrodeposition using horizontal electrodes and corrosion resistance, Journal of Coatings Technology and Research, 10 (2), 285-295.
Brenner, A., 1963. Electrodeposition of Alloys: Principles and Practice: General survey, principles, and alloys of copper and silver (Vol. 1). Academic Press.
Chen, L., Wang, L., Zeng, Z. ve Xu, T., 2006. Influence of pulse frequency on the microstructure and wear resistance of electrodeposited Ni–Al2O3 composite coatings. Surface and Coatings Technology, 201 (3-4), 599-605.
Golodnitsky, D., Rosenberg, Y. ve Ulus, A., 2002. The role of anion additives in the electrodeposition of nickel–cobalt alloys from sulfamate electrolyte, Electrochimica Acta, 47 (17), 2707-2714.
Gomez, E., Pane, S., Alcobe, X. ve Valles, E. 2006. Influence of a cationic surfactant in the properties of cobalt–nickel electrodeposits. Electrochimica acta, 51 (26), 5703-5709.
Hassani, S., Raeissi, K. ve Golozar, M.A., 2008. Effects of saccharin on the electrodeposition of Ni–Co nanocrystalline coatings. Journal of Applied Electrochemistry, 38 (5), 689-694.
Ishikawa, M. Enomoto, H. Matsuoka, M. ve C. Iwakura, 1994. Effect of tetraborate ions on electrodeposition of nickel-copper alloy from a pyrophosphate bath, Electrochimica Acta 39 (14), 2153–2157.
Landolt, D., 2002. Electrodeposition science and technology in the last quarter of the twentieth century, Journal of The Electrochemical Society, 149 (3), 9-20.
Lupi, C. ve Pilone, D., 2001. Electrodeposition of nickel- cobalt alloys: the effect of process parameters on energy consumption. Minerals Engineering, 14 (11), 1403-1410.
Lupi, C., Dell'Era, A., Pasquali, M. ve Imperatori, P., 2011. Composition, morphology, structural aspects and electrochemical properties of Ni–Co alloy coatings, Surface and Coatings Technology, 205 (23-24), 5394-5399.
Ma, C., Wang, S.C. ve Walsh, F.C., 2015. Electrodeposition of nanocrystalline nickel–cobalt binary alloy coatings: a review, Transactions of the IMF, 93 (2), 104-112.
Oriňáková, R., Turoňová, A., Kladeková, D., Gálová, M. ve Smith, R.M., 2006. Recent developments in the electrodeposition of nickel and some nickel-based alloys, Journal of Applied Electrochemistry, 36 (9), 957-972.
Srivastava, M., Selvi, V.E., Grips, V.W. ve Rajam, K.S., 2006. Corrosion resistance and microstructure of electrodeposited nickel–cobalt alloy coatings, Surface and Coatings Technology, 201 (6), 3051-3060.
Qiao, G., Jing, T., Wang, N., Gao, Y., Zhao, X., Zhou, J. ve Wang, W., 2006. Effect of current density on microstructure and properties of bulk nanocrystalline Ni–Co alloys prepared by JED, Journal of The Electrochemical Society, 153 (5), C305–C308.
Tury, B., Lakatos-Varsányi, M. ve Roy, S. 2006. Ni-Co alloys plated by pulse currents. Surface and Coatings Technology, 200 (24), 6713-6717.
Wang, L., Gao, Y., Xue, Q., Liu, H. ve Xu, T., 2005. Microstructure and tribological properties of electrodeposited Ni–Co alloy deposits. Applied Surface Science, 242 (3-4), 326-332.
Yang, Y.Y. ve Deng, B., 2011. Preparation of Ni-Co alloy foils by electrodeposition. Advances in Chemical engineering and science, 1 (02), 27.
Zhuang, Y. ve Podlaha, E.J., 2000. NiCoFe ternary alloy deposition: I. an experimental kinetic study, Journal of the Electrochemical Society, 147 (6), 2231-2236.