Electro forming

Plating of aluminium has been developed for electro forming wave-guides with wall thicknesses up to O-lOmm, and for the aluminium coating of reflectors. 

Copper is electrodeposited commercially mainly from cyanide, sulphate and pyrophosphate baths. For rapid deposition in electro-forming, a fluoborate bath may also be used. 

Irani and Callis (Ref 14) used two parameters of the distribution of ground monocalcium phosphate (which follows the commonly used log normal distribution law) namely, Mg and Og, the geometric mean diameter and the geometric standard deviation, to evaluate the precision and accuracy of electro-formed sieves vs sedimentation as a reference procedure ... 

Geometric mean diameter and 4.7% 4.6% standard deviation between electro-formed sieves sedimentation... 

To evaluate the effect of shape factors of particles, the electro-formed sieves were calibrated microscopically with two different materials ... 

Surfaces of cadmium with various morphological properties were electro-formed on the Cd electrode from sulfate solutions by varying current densities, temperature, and pulse electrolysis conditions [218]. The surface properties were defined by the values of slopes of quasi-steady state E versus logarithm current density dependencies and exchange current densities in 0.5 M CdS04 + 0.15 M H2SO4 solution. The dependence of the slope values on surface properties was explained in terms of the influence of crystallization overpotential. 

Use Alloys (low-alloy steels, stainless steel, copper and brass, permanent magnets, electrical resistance alloys), electroplated protective coatings, electro-formed coatings, alkaline storage battery, fuel cell electrodes, catalyst for methanation of fuel gases and hydrogenation of vegetable oils. 

The related processes for metal deposition include electroless deposition, immersion plating, and electro-forming. They follow the basic principles of electrochemistry. 

Figure 8.1 Examples of objects which are commercially electro formed (a) electric razor foils and (b) a glass mould. Photographs supplied by Berec Components Ltd.

Figure 8.2 Principle of the process for electro forming metal foil...

Spiro, P. ( 91 ) Electro forming. International Pubns Service, New York. 

Reaction injection molding creates its own resin by mixing two highly reactive liquid components which react with each other by high-pressure impingement. The reaction is completed shortly after the resin is injected into the mold. This is accomplished at a pressure of 100 Ib/in, which permits the use of electro-formed and vapor-formed nickel lined epoxy, aluminum, and kirksite tools at a considerably reduced tooling cost. (Machined and plated cast steel molds can also be used.) As a closed-mold process, both sides of the part are finished and can have textures, raised numbers, and raised letters, but molded-in labels are not feasible. The finished part can be trimmed in the mold. 

J. Docker and Th. Bolch, Nickel Electroforming — Some Aspects for Process Control . Frauenhofer Institute for Production Control and Automation Stuttgart, Presentation at Int. Symposium on Electro-forming/Deposition, Los Angelos, CA, USA 1983. 

Figure 63.21 shows two examples of fine trace produced by sputtering/electro-forming... 

The same processes of photohthography of plating resist, electro forming of the conductors, stripping of the resist and etching of seed layer are conducted to build the second conductor layer. 

Fig. 4.54. Production of the XEUS X-ray telescope (a) Zerodur mandrel, (b) electro-formed mirror segments, (c) telescope segment, (d) model of XEUS...

After being cut to size and having wires or tabs hot-forged onto an appropriately coined (compressed) area to carry current to the cell terminals, the electrodes are either electro-formed (charged in tanks against inert counterelectrodes) before assembly into cells or assembled into the cells in the metallic state and later charged in the cell. 

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