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Nanocomposite chromium coatings on aluminum alloys

Gidikova N., Valov R., Petkov V., Sułowski M., Witkowska M., Cempura G.

Prace Instytutu Odlewnictwa

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2017

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Vol. 57, no. 4

241--244

EN

Chromium coatings modified with nanodiamond particles were deposited on aluminum alloys. The concentration of the nanodiamond particles in the chrome plating electrolyte was from 5 to 25 g/l. The thickness of the layer varied between 30 and 70 μm. The layers were prepared with the same electrolytic conditions and were measured with a metallographic microscope. The maximum microhardness of the coating was 840 kg/mm2. X-ray diffraction analysis was performed with a Siemens D500 apparatus using the Bragg-Brentano technique. The distribution of Cr, Al and O in the cross section was studied by SEM-EDS. It was found that the layers were homogenous – only consisted of chromium. The coatings were also studied for non-destructivity by X-ray 3D computed tomography. It was found that the coatings were intact and continuous along the section. In order to obtain the maximum yield of chromium and maximum thickness of the layer, the optimum nanodiamond particle concentration was 10 g/l.

2

Composite Coatings of Chromium and Nanodiamond Particles on Steel

Gidikova N., Sulowski M., Petkov V., Valov R., Cempura G.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 4

2421--2424

EN

Chrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.

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HR TEM examinations of nanodiamond particles for biomedical application

Mitura K.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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Vol. 37, nr 2

317-322

EN

Purpose: The aim of the study is an analysis of a different type of nano-diamond powders on HR TEM (material characterisation, the normal distribution of grain size). These nano-powders were used in many biological researches and each of them had a special biological activity. Comparison between the material and biological properties of diamond powders answered many questions about the chemical and physical reactions on a boundary: diamond surface – living organism. Design/methodology/approach: In this work we used cytotoxicity assays using MTT test and HR TEM examinations. We examined the nanodiamond particles manufactured by detonation method, RF/MW PACVD method, RF PACVD method, pure diamond from De Beers Company and graphite powder as a control. Findings: In this subject the material characterisation of diamond powders are known but we examined a different type of powders and we manufactured some of these nanopowders in our laboratory. Practical implications: Nanocrystalline Diamond Coatings have many applications in various fields of medicine. Nanodiamond Particles are an extended surface of diamond powder. Biological research with endothelial and lung cancer cells are the introduction to application in human’s treatment. Originality/value: There are in vitro examinations with bioactive biomaterial. Nanodiamond particles have a very high bioactivity on cell level and inhibit cancerogenesis.