Composite Electrolytic Coatings Research Articles

Consolidation of Non-Conductive Cutting Elements of Abrasive Tool

The conditions for cladding of diamond and superhard macropowders with composite electrolytic coatings are studied. The coating characteristics are established to depend on the pretreatment, electrolyte concentration, current density, and deposition duration. The optimal coating layer 120–150 μm in thickness is produced at a current density of 2.5–3 kA/m2. The conditions for making composite materials from diamond-like clad powders by filed-associated sintering are examined. It is shown that current density and heating rate are the determining factors. The properties of a composite material become optimal at a current density of 8.28 · 106 A/m2 and a total sintering time of no longer than 120 sec. Tools made from such composite materials can be used for machining granite and marble. The performance of composite materials produced from clad superhard diamond macropowders is higher than that of materials from a mixture of cobalt and diamond powders.

Dependence of physicomechanical properties of a nickel-cobalt-aluminum oxide composite electrolytic coating on the dispersity of the alloying component

Effect of the dispersity of aluminum oxide on the microhardness, wear, internal stresses, and porosity of nickel-cobalt-aluminum oxide composite electrolytic coatings deposited from a chloride electrolyte and the dependence of the content of aluminum oxide in the coating on the agitation rate and working duration of the electrolyte were studied.

Саvitation-erosion wear resistance composite electrolytic coatings in neutral medium

The work presented technology of wear-resistant composite electrolytic coatings on nickel base. Composite coatings containing a filler consisting of silicon carbide powders of different factions nanopowders of up to 50 nm, 5 (M5) mk, 20/28 mk, 40/50 mk and amorphous B particle size of about 1 micron to form during the subsequent heat treatment of solid solutions. Accordingly, in the accepted designation: Ni-SiC nano ; Ni-SiC 5 ; Ni-SiC 28 ; Ni-SiC 50 . To form the CEP was established setting that lets you adjust the resistance of the near-electrode layer of electrolyte, which in turn, makes it possible to form CEP in a wide range of process parameters electrolysis both horizontally and vertically on the cathode. The novelty of the design of the installation is protected by a patent of Ukraine № 55154 from 10.12.2010. Investigation of cavitation-erosion wear resistance in hard water and in 3% solution of NaCl showed that CEP formed can be divided into 2 groups: group I - CEP SiC nano of Ni-and Ni-SiC 5 and group II - CEP of Ni-SiC 28 , Ni -SiC 50 . Therefore, to enhance cavitation-erosion wear resistance of parts of sodium chloride, particularly in sea water (3% solution of NaCl), the most effective CEP of SiC nano and Ni-SiC 5 (group I). Thermal annealing at 400 o C for 1 ... 2 hours increases the cavitation wear CEP Ni- SiC nano 20% in hard water and 30% in a solution of NaCl, due to the increase of microhardness and tension leveling coating and increase corrosion resistance by reducing the electrochemical heterogeneity. Vacuum annealing CTR with particles of silicon carbide and boron in 1080-1090 o C can obtain wool - dense and smooth coatings Kavita -ment of durability enhancement schuyetsya an average of more than 2-fold by the formation of a solid frame with eutectic Ni-Ni 3 B and borides Ni 3 B.

The investigation of influence of laser radiation on the structure and mechanical properties of composite electrolytic nickel coating

Purpose. Investigation of laser radiation effect on the structure and mechanical properties of electrodeposited nickel composite coatings containing ultrafine diamonds. Methodology. Electrodeposition of nickel films was carried out with the addition of a standard solution of ultrafine diamonds (UFD) on laser-electrolytic installation, built on the basis of the gas-discharge CO2 laser. Mechanical testing the durability of coatings were performed on a machine with reciprocating samples in conditions of dry friction against steel. The spectral microanalysis of the elemental composition of the film - substrate was performed on REMMA-102-02. Findings. Research of nickel coatings and modified ultrafine diamond electrodeposited under external stimulation laser demonstrated the dependence of the structure and mechanical properties of composite electrolytic coating (CEC), and the qualitative and quantitative distribution of nanodiamond coprecipitated from an electrodeposition method. Originality. The effect of laser light on the process of co-precipitation of the UFD, which increases the micro-hardness and wear resistance of electrolytic nickel coatings was determined. Practical value. The test method of laser-stimulated composite electrolytic nickel electrodeposition coating is an effective method of local increase in wear resistance of metal coatings, which provides durability save performance (functional) properties of the surface.

Properties of composite nickel-cobalt-aluminum oxide coating deposited from chloride electrolyte

Effect of the cathodic current density, pH value, electrolyte temperature, and concentration of aluminum oxide introduced into the electrolyte on the wear, microhardness, and internal stresses in nickel-cobalt-aluminum oxide composite electrolytic coatings was studied. It is shown that the coatings under consideration can be used instead of chromium coatings.

ЗНОСОСТіЙКіСТЬ ЯК ЕНЕРГЕТИЧНА ХАРАКТЕРИСТИКА МіЦНОСТі МАТЕРіАЛУ В ЗОНі ТЕРТЯ

The purpose of the research is to investigate the destruction processes in coating materials during friction. These researches have been conducted on composite electrolytic coatings with titanium carbide and silicon carbide powders used as fillers. The assessment of surface layer destruction has been performed using the methods of theoretical and experimental research results analysis as part of an energy model based on wear particles formation in surface areas of a friction pair. Besides, the dependence of wear particle size on the mechanical properties of material has been determined. The analysis shows that material is destructed faster for carrying particles of larger sizes during friction. This means that materials with a higher hardness have a smaller size of carrying particle and materials with higher strength have a bigger size of carrying particles

Effect of nanodiamond modification on the characteristics of diamond-containing nickel coatings

We have studied composite electrolytic coatings grown from a nickeling electrolyte containing detonation synthesis nanodiamond. The results demonstrate that the surface composition of nanodiamond particles influences the structure and properties of the coatings. The use of nanodiamond with a surface modified by nickel compounds raises the microhardness and wear resistance of the nickel coatings, without degrading their plasticity.

Electrochemical and corrosion properties of composite electrolytic and galvanic Ni-based coatings. II. Corrosion resistance of thermally treated coatings

The paper examines the potential for increasing the corrosion resistance of composite electrolytic and galvanophoretic coatings under thermal treatment. The corrosion behavior of the coatings in a 3% NaCl solution is analyzed under various conditions of thermal treatment. It is established that thermal treatment of composite electrolytic Ni-B and Ni-Ti coatings has no effect on the corrosion resistance of the electrolytic coating itself or that placed on a substrate. At the same time, the galvanophoretic Ni-B-Mo 2 C coating shows high corrosion resistance after thermal treatment at 1100°C owing to the obliteration of porosity during liquid-phase sintering.

Electrochemical and corrosion properties of composite electrolytic and galvanic Ni-based coatings. I. Electrochemical and corrosion properties of composite electrolytic coatings

The corrosion behavior of composite electrolytic nickel-based coatings in 3% NaCl solution is examined. The corrosion resistance of coatings as a foil and coatings on a steel substrate is compared. The corrosion properties of composite Ni–B and Ni–Ti electrolytic coatings are shown to be consistent with those of pure Ni.

Residual stress in Nb3Sn-based composite electrolytic coatings

A combined nondestructive technique utilizing X-ray diffraction strain measurements has been developed for evaluating the residual stress and Poisson’s ratio in Nb3Sn-based composite electrolytic coatings. The magnitude and nature of the residual stress in niobium stannide on molybdenum, nickel, and copper substrates have been determined.

Latest Informations and View of the Ultra-dispersed Nano-diamonds

The structural characteristics of the ultra-dispersed diamonds are the size of 10 nm grain, diamond core, interlayer of non-diamond carbon, and outermost layer of surface groups. By making the best use of forementioned characteristics, the applications in the market are for super precise polishing, lubricant, composite electrolytic coatings, deodorization and antimicrobial use. Due to their uniqueness, it is highly expected that the expansion of their application into the field of flat panel display, car electronics, and biotechnology will happen with efforts at improvement in the grain diameter control, purity control, the surface modification control and the lattice defect control technology.

Synergistic effect in nickel-Teflon composite electrolytic coatings

The possible synergistic effect in the manifestation of the wear resistance and antifriction properties of nickel-Teflon composite electrolytic coatings was analyzed. The results of calculations of the diagnostic properties of the coatings in terms of the “concentration-wave” model are discussed in comparison with the corresponding experimental data.

The state of the art and prospects of detonation-synthesis nanodiamond applications in Belarus

Technological features of the commercial production of detonation-synthesis nanodiamonds at the SINTA Joint-Stock Company and the characteristics of the nanodiamonds and diamond-containing mixtures produced are considered. Nanodiamond applications in the production of composite electrolytic coatings that are based on chromium, nickel, gold, and silver, exhibit good service properties, and save on the use of noble metals and electric power are exemplified. Nanodiamond applications for the modification of plastics, antifriction lubricants, and oxide coatings grown by microarc oxidation of aluminum alloys are also considered. The prospective application of nanodiamonds as a raw material in the synthesis of diamond powders and superhard composites by static and shock-wave loading is demonstrated.

Effect of a strengthening phase on the structure and some mechanical properties of electrolytic coatings based on nickel

An investigation was made of the composition, structure, microhardness, and tribological properties after thermochemical treatment of composite electrolytic nickel-based coatings with various additions. It was established that the mear resistance of nickel-boron-diamond coatings in sliding friction without lubrication depends upon the nature and amount of added inclusions, and the mechod of treatment.

Formation of the structure of composite electrolytic coatings based on nickel in heat treatment

Formation of the structure of composite electrolytic coatings based on nickel in heat treatment

Structure and properties of nickel-chrome diboride composite electrolytic coatings

The addition, to the CEC based on nickel, of up to 6% fine-dispersion powders of chrome diboride (in their position in the vertical cathode) and of more than 16.4% micropowders (on the horizontal cathode) with subsequent vacuum annealing at temperatures ranging from 400 to 1100°C makes it possible to produce wear and corrosion-resisting coatings of three types: the coatings consisting of a nickel matrix alloyed with chrome, with uniformly distributed inclusions of Ni3B, coatings consisting of an eutectic boride frame filled with a solid solution of chrome in nickel, and coatings consisting of an eutectic boride matrix which contain specially oriented columnar crystals of the boride of complicated composition (Ni2CrB2).

Composite boride coating structure forming under conditions of low-temperature annealing

Direct experimental observation has been used for the first time to study the process of low-temperature formation of borides in composite electrolytic coatings. During the codeposition of nickel and boron, crystallostructural disturbances are produced as a result of the formation of cloudlike intertwined dislocation arrays and twinning of nickel. With amorphous boron, the experimentally established temperature threshold of nickel boride formation is 400°C. The boride formation process is accompanied by dislocational transformation of nickel grains from cloudlike intertwined arrays to a cellular structure. During the formation of borides the shape of the grains of the boron-containing phase changes from branched (in the starting condition) to spheroidal. The growth of Ni3B grains in boride rosettes is accompanied by the formation of a boride skeleton in the coating structure.

Wear-resistant composite electrolytic coatings based on nickel and iron

Wear-resistant composite electrolytic coatings based on nickel and iron

Composite nickel-boron electrolytic coatings : Fedorchenko, I.M., Guslienko, Y.A. and Epik, A.P. Soviet Powder Metallurgy and Metal Ceramics, Vol 11, no 8 (Aug 1972) pp 626–628

Composite nickel-boron electrolytic coatings : Fedorchenko, I.M., Guslienko, Y.A. and Epik, A.P. Soviet Powder Metallurgy and Metal Ceramics, Vol 11, no 8 (Aug 1972) pp 626–628

Composite nickel-boron electrolytic coatings

1. The feasibility has been demonstrated of producing composite Ni-B electrodeposits with a uniform distribution of boron particles throughout their matrix. 2. Diffusional annealing leads to the formation of qualitatively new structures in such deposits and improves their physicomechanical characteristics. 3. The wear resistance of heat-treated Ni-B deposits is as high as, and frequently much higher than, that of hard chromium electrodeposits.