Papers by Keyword: Electroforming

Abstract: The metal/C-based multilayer film with high reflectivity is the “workhorse” in today's optical application, and NiCo electroforming offers a promising prospect in contemporary optical production. Therefore, the NiCo electroforming was performed on metal/C-based multilayer film in this study, and the obtained deposition structure and electrochemical mechanism were discussed. The results show that the Ni electrodeposition on Ru/C multilayer film obeyed the three-dimensional (3D) continuous nucleation process under diffusion control, which was in accordance with the crystal growth characteristics. This work confirmed the feasibility of direct NiCo electroforming on Ru/C multilayer film, and provided a theoretical backing for the fabrication of metal/C-based multilayer mirror.

Abstract: The process parameters of fundamental electroforming solution were optimized firstly. Furthermore, some pure copper electroforming samples were prepared in the condition of different nana La₂O₃ addition quantity. Three main material properties evaluated. In addition, the EDM machining experiments were conducted to verify the characteristics of electrical corrosion resistance resulting from the prepared copper tube electroforming samples for cooling hole of Inconel718 nickel alloy. EDM experimental results demonstrate that copper electroforming layer with grain size 15.9μm, microhardness 98.2HV, with 1.2g/L addition quantity of nana La₂O₃, and its electrode loss rate decrease 13.29% and 7.26% than pure copper and copper electroforming layer without nana La₂O₃ addition respectively.

Abstract: Palmtop tensile and fatigue testing machines were developed in-house for small and thin specimens that were fabricated by the LIGA process. The dimensions of the specimens were selected in accordance with the international standard IEC62047-3, and were 10 micrometers in thickness, 20 micrometers in width, and 500 micrometers in parallel length. Since the loading mechanism and methods of measuring the load and displacement were specially designed, the stiffness of the specimen is quite low compared to that of the conventional large-size specimens. The mechanical properties of electroformed Ni₂Pd₈ and Ni₄Pd₆ alloys were studied with these developed testing machines and excellent values of tensile and fatigue strengths of 2.7 GPa and 1.8 GPa, respectively were obtained in the case of the Ni₄Pd₆ alloy.

Abstract: We develop a simple and competitive fabrication of antireflective (AR) films with high-ordered nanostructure arrays on polycarbonate (PC) substrate by using gas-assisted hot embossing and a self-assembled technique. In this method, a self-assembled monolayer of polystyrene (PS) nanospheres is well-patterned on glass substrates as the first template. Subsequently, we use the plasma sputtering to deposit a conductive layer onto the surface of nanosphere (NS) patterned substrates, and then, electroforming is applied to fabricate a nickel mold with an inverse shape of nanospheres. In the last step, a unique glass transition is utilized to duplicate nanostructures on PC films via gas-assisted hot embossing. Not only in visible light but in near infrared, the optical properties of this AR film are similar or better than for other methods. This fabrication process also has great potential in industry, with its simplicity, large-area but low-cost.

Abstract: This work deals with a development of a tool for ear ventilation tube production. Ear tubes are medical devices, which allow ventilation and provide pressure equalization in the middle ear cavity for prolonged period of time; in case of repetitive inflammation. These implants are normally made from metals or classical polymeric materials. Whereas, today, the effort is to develop bioresorbable tubes based on polylactic acid, which could replace currently used material. The benefit provides no requirement of secondary surgery for their removal. The size of ear implants is only in millimetres and the tool for their manufacturing requires a special technology. In this paper, two tubes and a transfer mold for their production was designed using 3D CAD software Catia V5R18. Subsequently, the special manufacturing process for the mold cavity plates using the rapid prototyping and electroforming technology was proposed. The designed tool is intended for biodegradable tubes, which will be further tested in the laboratory.

Abstract: Ni-CeO₂ nanocomposites were electrodeposited using rotating cylindrical cathode in ultrasonic field. The surface morphologies and the CeO₂ contents in the nanocomposite were examined by the Scanning Electron Microscopy and the Energy Disperse Spectroscopy. The microhardness of nanocomposites were also evaluated by digital microscopical Weis Sclerometer. The effect of ultrasonic power and cathode rotating speed on the CeO₂ nanoparticles contents and the distribution condition of the nanocomposites were investigated. The results indicate that both the ultrasonic power and cathode rotating speed effect the microstructure and property of the nanocomposites remarkably. Prepared under the technology parameters of cathode current density 4A/dm², cathode rotating speed 1200rpm, CeO₂ nanoparticles addition 40g/L and ultrasonic power 300W, the Ni-CeO₂ nanocomposites present refined crystal grains, compact microstructure, smooth surface morphology and high microhardness.

Abstract: New biodegradable Fe-Zn alloys with different concentration of zinc were prepared by electroforming in this paper. The composition, phase and microstructure of the Fe-Zn alloys were investigated by EDX, XRD and SEM, respectively. The potentiodynamic polarization and static immersion test were used to evaluate the in vitro biodegradation properties of these alloys. The results revealed that the alloys consist of single-phase Fe-Zn solid solution and have a better degradation property than pure iron, which make it a potential material used for bioabsorbable endovascular stent.

Abstract: Elecform3D^TM is a analysis and simulation tool of electroforming process, in order to facilitate design and manufacturing tasks. Electroforming is an electrolytic process that enables the manufacture of metallic parts with good mechanical properties with a high level of accuracy and reproducibility. In this process a thin metallic shell is deposited on a model part and later released from it. Distribution of deposited metal is not uniform due to current density distribution on the cathode. The results obtained with the first version of this product were very promising, and also indicated the need for a more precise analysis of electrochemical phenomena in this process.The methodology is based on the well-known potentials model of LaPlace, it enables deposited metal distribution prediction with high grade of precision, being experimentally validated with cathodic polarization curves. These boundary conditions at the electrodes serve to combine the existing electrical and chemical effects in the process. On the active surfaces of the electrodes the current density is a function of the nonlinear laws of polarization in the electrode-electrolyte interface. Analytically the resolution of these problems is totally unworkable, at least for real geometries, so it is used for solving the employment of numerical methods. The resolution has been considered using the boundary element method (BEM), because we are only interested in obtaining the solution on the surface of the cathode. Elecform3D^TM is an important step beyond electroforming so far, and combined with almost all additive manufacturing 3D printer, is a cheaper alternative for high quality metallic parts manufacturing in comparison with other Rapid Manufacturing technologies.

Abstract: Electroforming technology is an important part of micro fabrication andfine parts and composite materials prepared by the electroforming technology has broad application prospects. This paper describes the principle and method of electroforming, introduces the development and the basic elements of electroforming, then concludes the research status and main research direction and trend of this technology.

Abstract: Basing on an inert perforated metal mask, a hybrid electrochemical fabrication combining electroforming and mask electrochemical machining was proposed to manufacture metal through-hole array with double tapered openings. The feasibility of this novel process was investigated experimentally. The effects of pattern parameters of inert metal mask, such as wall angle, α, substrate thickness, H, hole spacing, L and hole size, D, on profiles of the resulting holes were analyzed. The experimental results show that the hybrid fabrication is able to manufacture high-aspect-ratio double tapered hole array with good surface quality.