Analiza tvrdoće i morfologije elektrolitički dobijenih bakarnih prevlaka

The influence of various electrolysis parameters, such as selected operating current regime, the cathode material type, composition and mixing conditions of the electrolyte and electrodeposition time, on the structural-morphological characteristics of the copper coatings has been investigated. Morphology and structure of the coatings were analyzed by scanning electron microscope (SEM) and atomic force microscope (AFM). Characterization of mechanical performance, such as microhardness of the coating, was done using the Vickers microindentation test. The absolute hardness of Cu coatings was determined by application of the composite hardnes models, named the Chicot−Lesage (C−L). Based on this model, it is determined the critical relative indentation depth (RID)c of 0.14, independent of all examined parameters of the electrodeposition. Depending on the electrolyte type, two different Cu coatings were obtained: fine-grained microcrystalline coatings with a strong (220) preferred orientation from the basic sulfate electrolyte and smooth mirror bright nanocrystalline coatings with a strong (200) preferred orientation from the electrolyte with added leveling/brightening additives. The „softening effect“ of mirror bright coatings obtained in the presence of a combination of additives is explained by the grain boundary phenomenon. Two different substrates: monocrystalline silicon Si(111) and polycrystalline brass alloy, were selected for comparative analysis of composite hardness.Istražen je uticaj različitih parametara elektrolize, kao što je izbor radnog režima struje, katodnog materijala, sastav i uslovi mešanja elektrolita i vreme taloženja, na strukturno-morfološke karakteristike bakarnih prevlaka. Analizirana je morfologija i struktura prevlaka pomoću skenirajućeg elektronskog mikroskopa (SEM) i mikroskopa na principu atomskih sila (AFM). Karakterizacija mehaničkih performansi, kao što je mikrotvrdoća prevlaka, urađena je korišćenjem mikro utiskivača po Vikersovom testu. Apsolutna tvrdoća bakarnih prevlaka je određena primenom modela kompozitne tvrdoće, pod nazivom Šiko−Lezaž (Š−L). Na osnovu ovog modela određena je kritična relativna dubina utiskivanja (RDU) od 0,14 koja je bila nezavisna od svih ispitivanih parametara elektrohemijskog taloženja. U zavisnosti od tipa elektrolita, dobijene su dve različite prevlake bakra: sitnozrna mikrokristalna prevlaka bakra iz osnovnog sulfatnog elektrolita sa izraženom (220) preferencijalnom orijentacijom i glatka ogledalasto sjajna nanokristalna prevlaka bakra sa izraženom (200) preferencijalnom orijentacijom iz elektrolita sa dodatkom aditiva za poravnanje/sjaj. „Efekat omekšavanja” ogledalasto sjajnih prevlaka dobijenih u prisustvu kombinacije aditiva je objašnjen preko fenomena uticaja granice zrna. Za uporednu analizu tvrdoće kompozita odabrana su dva različita supstrata: monokristalni silicijum Si(111) i polikristalna legura mesinga

Influence of Parameters and Regimes of the Electrodeposition on Hardness of Copper Coatings

Correlation among morphological, structural and hardness characteristics of electrodeposited copper coatings is presented in this review paper. Cu coatings were produced applying constant galvanostatic (DC) and pulsating current (PC) regimes on hard silicon (Si(111)) and brass substrates. The parameters of the electrochemical deposition which include the kinds of electrolyte and cathode, the coating thickness and the electrolyte stirring, as well as the parameters defining PC regime, such as the average current density and the current density amplitude, were analyzed. Morphology and structure of Cu coatings were examined by scanning electron microscope (SEM), atomic force microscope (AFM) and by X-ray diffraction (XRD), while hardness was examined by Vickers microindentation. The coatings of Cu on both Si(111) and brass cathodes belong to “soft film (coating) on hard substrate” composite hardness system, and the Chicot–Lesage (C–L) composite hardness model was applied to estimate a hardness of the Cu coatings. Analyzing the examined parameters and regimes of electrodeposition, the critical relative indentation depth (RID)c of 0.14 has been defined by the C–L model. Based on done analyses, it is shown that this RID value, separating a zone where measured hardness corresponds to the coating hardness and a zone where it is necessary to apply the C–L model to determine an absolute hardness of the Cu coatings, has an universal character for the electrolytically produced Cu coatings on Si(111) and brass substrates

Одређивање апсолутне тврдоће електролитички добијених превлака бакра применом Chicot-Lesage композитног модела тврдоће

In this study, a novel procedure, based on application of the Chicot–Lesage (C–L) composite hardness model, was proposed for the determination of an absolute hardness of electrolytically produced copper coatings. The Cu coatings were electrodeposited on the Si(111) substrate by the pulsating current (PC) regime with a variation of the following parameters: the pause duration, the current density amplitude and the coating thickness. The topography of produced coatings was characterized by atomic force microscope (AFM), while a hardness of the coatings was examined by Vickers microindentation test. Applying the C–L model, the critical relative indentation depth (RID)c of 0.14 was determined, which is independent of all examined parameters of the PC regime. This RID value separated the area in which the composite hardness of the Cu coating corresponded to its absolute hardness (RID <0.14) from the area in which the application of the C–L model was necessary for a determination of the absolute coating hardness (RID ≥ 0.14). The obtained value was in a good agreement with the value already published in the literature.Предложен je нови поступак заснован на примени Chicot–Lesage (C–L) композитног модела тврдоће за одређивање апсолутне тврдоће електролитички добијених превлака бакра. Превлаке бакра су електрохемијски исталожене на силицијуму (111) оријентације режимом пулсирајуће струје варирањем следећих параметара: трајање паузе, амплитудна густина струје и дебљина превлаке. Топографија произведених превлака је окарактерисана микроскопијом атомских сила, док је тврдоћа превлака испитивана Викерсовим тестом утискивања. Применом C–L композитног модела тврдоће, одређена је критична релативна дубина утискивања (RID), од 0,14, која је независна од свих испитиваних параметара режима пулсирајуће струје. Ова вредност раздваја област у којој композитна тврдоћа превлаке може да се изједначи са њеном апсолутном тврдоћом (RID << 0,14) од области у којој је неопходно применити C–L модел за одређивање апсолутне тврдоће превлаке (RID ≥ 0,14). Добијена вредност RID показује добро слагање са вредностима публикованим у литератури

Morphology, structure and hardness of electrolytically produced copper coatings

Poster presented at: 4th International Congress of Chemists and Chemical Engineers of Bosnia and Herzegovina, June, 30th-July, 02nd, Sarajevo, Bosnia and HerzegovinaAbstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5213

Effect of concentration pigment particles on microstructure of the metal matrix copper composite coatings

This research focuses on the synthesis and characterization of composite coatings via electrochemical route with co-deposition pigments. For that reason, the effect of adding yellow green phosphorescent pigment on microstructural evaluation of the Cu/pigment composite systems has been investigated.Second International Conference on Electron Microscopy of Nanostructures ELMINA 2022, August 22nd-26th, 2022, Belgrade, Serbia

Influence of intensity of ultrasound on morphology and hardness of copper coatings obtained by electrodeposition

The influence of various intensities of ultrasound applied for the electrolyte stirring on morphological and mechanical characteristics of electrolytically produced copper coatings has been investigated. The copper coatings produced by the galvanostatic regime of the electrodeposition from the basic sulphate electrolyte and the electrolyte with added levelling/brightening additives at the low temperature were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques (surface morphology and topography, respectively) and by Vickers microindentation (hardness). The roughness of coatings increased with the increasing intensity of ultrasound, indicating that morphology of the coatings worsened with the enhanced application of ultrasonic waves. This is attributed to the strong effect of ultrasound on hydrodynamic conditions in the near-electrode layer, which is manifested by the increase of share of the activation control in the mixed activation-diffusion control of electrodeposition with increasing the intensity of ultrasound. The concept of "effective overpotential" originally proposed to explain a change of surface morphology in the conditions of vigorous hydrogen evolution is also applicable for a change of morphology of Cu coatings under the imposed effect of ultrasonic waves. Hardness analysis of the coatings showed that an intensity of applied ultrasound did not have any significant effect on the hardness, especially for the Cu coatings produced from the basic sulphate electrolyte

Influence of parameters of the pulsating current (PC) regime on morphological, structural and hardness characteristics of copper coatings electrodeposited on Si(111)

Electrodeposition of Cu was performed on Si(111) by the pulsating current (PC) regime in the range of the average current densities (jav) between 15 and 70 mA cm-2 . The selected values of the average current densities were attained by varying either pause duration (tp: 28.3, 15, 7.5 and 5 ms, i.e. jav: 15, 25, 40 and 50 mA cm-2 for the constant values of deposition pulse of 5 ms and current density amplitude (jA) of 100 mA cm-2) or amplitude of the current density (jA: 120 and 140 mA cm-2 , i.e. jav: 60 and 70 mA cm-2 for the constant values of deposition pulse of 5 ms and pause duration of 5 ms). Morphological and structural characteristics of the obtained coatings were examined by scanning electron microscope (SEM), atomic force microscope (AFM) and X-ray diffraction (XRD), respectively. With increasing the average current density, morphologes of the coatings changed from those with large and well defined crystal grains obtained at jav of 15 mA cm-2 (the dominant effect of activation control) to fine-grained obtained at jav of 50 mA cm-2 (the mixed activation-diffusion control) and those with globules when diffusion becomes a dominant process (jav = 70 mA cm-2). The minimum roughness showed the Cu coating obtained at jav of 50 mA cm-2 . Simultaneously, crystal structure changed from the strong (220) to the strong (111) preferred orientation with increasing average current density. The change of surface morphology was discussed by the effect of applied parameters of the PC regime on the type of electrodeposition control, while change in crystal orientation of produced coatings was explained by various rates of growth on various crystal planes. Hardness analysis of the produced coatings was performed by application of the Chicot-Lesage (C-L) composite hardness model. By application of this model, the relative indentation depth (RID; where RID = h/d; h is an indentation depth, and d is a thickness of coating) of 0.14 was established as the limiting value separating the area of the absolute hardness of the Cu coatings (RID < 0.14) from the area in which application of the C-L model is necessary for a determination of the absolute hardness of coatings (RID > 0.14). For RID < 0.14, the measured composite hardness corresponded to the absolute hardness of the coating

Application of copper electrodeposition processes in visualization of latent fingerprints obtained on various substrates

In this study, a basic sulfate electrolyte for electrochemical copper deposition and a sulfate electrolyte with additives to improve coating quality were used. It has been shown that for the visualization of latent fingerprints, it is better to use an electrolyte without additives. The use of electrolytes with additives has not been shown to be adequate for these purposes due to the effect of filling fingerprint ridges and reducing contrast

Optimization of electrodeposition parameters to improve composite hardness of nickel coatings on brass substrate for varying film thicknesses and applied indentation loads

In this investigation, nickel coatings were electrodeposited on brass substrate. The effects of electrodeposition process parameters such as, current density and deposition time (coatings thickness), on surface morphology and composite hardness values were studied. The value of the measured composite hardness by Vickers microindentation technique of the selected “hard film on soft substrate” composite system type depends on the applied indentation loads. For this reason, the microindentation loads are also included in the analysis. According to the experiment plan obtained by Design-Expert software, nickel coating has been produced on the brass cathode using galvanostatic regime (DC) with magnetic stirring of the electrolyte. The nickel sulphamate electrolyte with saccharine additive was used for Ni electrodeposition. Then, response surface methodology (RSM) was used to establish an adequate mathematical model. Subsequently, a mathematical model was developed to weight the effects of each input parameters (coating thickness, current density and indentation load) on the output parameter (composite hardness) of electrodeposited nickel coatings on brass substrate. According to the obtained results, the coating thickness and indentation load greatly influenced resulting composite hardness. On the other hand, coating current density primarily influenced microstructure and surface roughness. The topographic modification of the Ni coating surface depending on the post-treatment (mechanical and chemical) after deposition was studied using AFM microscopy

Mechanical Properties of Biomass-derived Silica Nanoparticles Reinforced PMMA Composite Material

Rice husk was used to produce silica particles, which were then used to reinforce the polymer matrix. The synthesized SiO2 particles were characterized using X-ray diffraction, Fourier transforms infrared spectroscopy (FTIR) and scanning electron microscopy with EDS. In a PMMA matrix, prepared SiO2 particles in amounts of 1, 3, and 5 wt.% were used as reinforcing agents. The goal of this research was to see if SiO2 particles had any effect on the mechanical properties of polymer composite materials. The morphology of the composites was examined using a field emission scanning electron microscope (FE-SEM). Vickers microindentation hardness and impact testing were used to determine the mechanical properties of the obtained composites. The indentation creep’s behavior of a polymethylmetacrylate (PMMA) composite material with varying amounts of nanoparticles (SiO2) was investigated and analyzed