Papers by Keyword: Plating

Abstract: Electroplating on polymer substrates, which provides polymers with enhanced mechanical properties, extended component lifetimes, and offers a decorative appearance, is environmentally unsustainable. Laser machining, a green process developed at Cirrus Materials Science Ltd, generates an array of pores on various polymer surfaces, which replaces the chemical etch process, and provides strong adhesion for metal coatings to polymer substrates. Laser machining is also applicable to a wide range of engineered or industrial polymer substrates and is adaptable to complex shapes and 3D printed parts. This paper discussed the process of laser machining of polymer substrates including the properties of metal layers on such machined surfaces; and demonstrated laser machining as a promising substitute for conventional chemical etching to prepare various engineering polymer substrates for adhesive coatings.

Abstract: Established the possibility of galvanochemical obtaining of a plating stronger than in case of chrome precipitation. Proposed precipitation of ternary alloy Co-Мо-W, which allows using the effect of synergism. Proposed and researched usage instead of sulphate-anhydride electrolyte – citrate-diphosphate and ammonia-citrate one. Achieved an increase in current efficiency of precipitated alloy and decrease in current efficiency of hydrogen, with respect to chrome precipitation, which increased safety of the galvanochemical industry. Selected the optimal ratios of components in citrate-diphosphate and ammonia-citrate electrolytes for ternary alloy Co-Мо-W precipitation. Determined the parameters of electrical effect for the galvanic process: constant current – j = 2–8 А/dm², pulse unipolar current – j = 4–20 А/дм². Achieved a high microhardness of this plating and high adhesion to base surface. Achieved greater safety of the galvanochemical technological process of ternary alloy Co-Мо-W application compared with chromium plating.

Abstract: Cladding of steel is mainly carried out by hot rolling. This process is very labor-intensive and, therefore, expensive. Cold plating has been used successfully to produce bimetals and could also be an alternative manufacturing process for cladded carbon steel composites. So far, however, only thin narrow IF-steels sheets were successfully cold plated. Different pretreatments and process windows have been used to successfully produce a cold roll-cladded composite of various steel grades on a cold rolling test facility. While joining two similar steels was relatively easy, the combination of different steel alloy compositions was more difficult. Higher necessary forces and edge cracks complicated the experiments. A slight warming of the sheets before joining had a positive effect on the production of the composite. From today's perspective, the required high rolling forces do not allow scaling up to large-scale production.

Abstract: Multiple use of pan concentrate from placer deposits directly in technical process without prealltoment of pure components could become one of promising directions in the field of receiving wide range of multicomponent metal and ceramic powdered materials. In this paper as the object of comparative examination, we present the hemimethylated plating made of exploited experimentative flux cored wires based on industrial Ni-Cr-B-Si system powder modified with rare-earth elements of concentrated complex from Tomtor mineral assets Republic of Sakha (Yakutia). The structure of received plating is heterogeneous and has oxidation coating as boundaries. According to the data of the phase shift analysis plating predominantly consist of Fe-Ni austenitic alloy phases with the Cr, Si carbide and Cr boride precipitation strengthening, plating generally consist of Al2O3, Cr2O3 и Fe2O3 oxide. The research of the plating ultimate composition testifies the equable allocation of main and alloying elements, local location of some elements in the structure of the plating. Microhardness of flux cored wire plating substantially depends on composition and fabricated structure. It has been established that the introduction of rare earth elements provided the formation of strengthening phase with the high hardness of plating resulting in wear resistance increase.

Abstract: Nickel foam-based Ni-Mo alloy electrodes, Ni+Mo composite electrodes and Ni+Mo/Ni-Mo composite alloy electrodes were prepared by eletrodeposition, and the electrocatalytic characteristics for hydrogen evolution reaction (HER) in 30wt% KOH solution were investigated by cathode polarization curve and electrochemical impedance spectroscopy (EIS). The experimental results show that in comparison with nickel foam electrodes, these electrodes exhibit a lower overpotential, a higher exchange current density and a larger real surface area for HER. At 30°C and current density of 200 mA/cm², the overpotentials of foam Ni electrodes, nickel foam-based Ni-Mo alloy electrodes, Ni+Mo composite electrodes, Ni+Mo/Ni-Mo electrodes are respectively 506, 252, 336, 202 mV. The nickel foam-based Ni+Mo/Ni-Mo composite alloy electrode had the highest HER electrocatalytic activity.

Abstract: In this study the bonding properties of three layer-plated aluminum sheets are investigated. The alloys applied in specific layers were as follows: AlMn1Si0.8 (core alloy) and AlSi10 (liner). The bonding was performed on a Von Roll experimental roll mill using hot rolling. The experimental temperatures were 460, 480 and 500 °C, respectively. To qualify bond development, T-peel test was used. The test was performed using an Instron universal material testing machine. T-peel test can be well used for the qualification of bond strength as the peel-off force and bond value developed on contacting surfaces are proportional. In addition to T-peel test, optical micrographs and SEM micrographs were also captured, in which typical bond faults were sought. The study aims at modelling the technology used in industry and exploring some typical bond faults as well as suggesting the causes generating these and their remedy. The impact of surface roughening before heating was studied as well. Also, the study aimed at confirming the suitability of T-peel test to qualify bond strength.

Abstract: Paper presents necessity of metal plating in the case of highly corosion process acting on metal pieces. By authors researches, the welding plating method has some disadvantages, possible to be eliminated by using the ultrasonic field. The work presents a series of experimental results obtained in the case of metal plating using welding method [10] with or without ultrasonic field. There were analised the main coupled material resulted functional properties and the final microstructure in the distinctive zone: base material, thermal influenced zone, and addition material.

Abstract: The paper presents the process of cladding surfaces required strong corrosion of parts in the chemical, petrochemical and engineering industry. The phenomenon of the factors that influence the dilution that occurs between the filler material and the base material and the technological processes possible to achieve efficient plating. Following technical and economic analysis establishes that process arc welding argon environment is a process that can be used optimally to plating. It presents experimental results obtained after plating surfaces of parts of the petrochemical industry, the functional characteristics of materials resulting torque in all three major areas (base material, heat affected zone and weld material), structural analysis and possible defects that may occur after the plating process.

Abstract: Nanocrystalline CoFe films were fabricated by electrodeposition process for an investigation of the relationship between the alloys’ characteristics and their magnetic properties. The study shows that coating thickness promotes softer magnetic properties of the films, and induces changes of film roughness, preferred orientation and domain pattern. The preferred orientation of the ~1 μm films (thin films) is (110) plane, whereas that of the ~3 μm films (thick films) are (110) and (200) planes. The magnetic domain of the thin films exhibit a stripe-liked pattern, whereas a bubble-liked pattern appears in the thick films. Iron content significantly affects the magnetic properties of the thick films. In this study, the 57.3wt.%Fe thick film has the highest saturation magnetization, and the 80.0wt.%Fe thick film shows the lowest coercivity.

Abstract: In this article, the corrosion behavior of the gold plating and the silver plating specimens are studied. It is found that the airtightness have effects on the contact properties of the different plating specimens. The surface morphology of specimens is observed by stereoscopic microscope and scanning electron microscope (SEM). Chemical constitution was examined by X-ray energy spectrum. The contact resistances were measured by four-point method. The experiment results show that the corrosion appearance of the silver plating is severer than that of the gold plating one after airtightness test. The corrosion degree of plating specimens decreased with the increase of the coatings thickness. The static contact resistances of corrosive spots appear higher contact resistance than normal value. It is found the high and unstable contact resistance of the corrosion products is more likely to cause contact failure. The influencing factor of the corrosion products with different plating has an important influence on the airtightness test and the contact failure of electric connector.