A. Selim PARLAKYİĞİT - 13th Week Missed Terms

High Speed Plating

Plating at high speed, at high current density, can usually only be justified if the process is cheaper or the product superior to a conventional rate plating procedure. The advantages of high speed plating are obvious in that a greater throughout can be achieved with a particular plant, or a smaller plant can be employed to provide a given output. The details of capital investment and overheads become the concern of the accountant but only if a technically viable process can be developed. High-speed processes are more demanding with regard to plant requirements, and some attempts have failed due to equipment deficiencies. The properties of electrodeposits produced at high current density are differnt from those of deposits obtained at conventional rates and they are superior for some purposes.

(Nickel and Chromium Plating, J.K.Dennis, T.E.Such, Page 423)

Vibratory Agitation

Research on vibratory agitation has been carried out using a commercial vibromixer with a motor operating at 50Hz. Both flat and perforated discs were employed; the latter are preferable so that the disc does not operate as an hydraulic piston which uses large amounts of energy to produce little mass agitation.

Various types of agitation patterns were studied. Vibrational agitation is reproducible and is controllable by the input voltage or power to the motor of vibromixer. The use of Reynolds number to characterize the agitation was proposed where Re = 2fad/v; a is amplitude, if is the frequency, d the diameter of the disc and v is the solution viscosity. A transformation from laminar to turbulent conditions occured at a Reynolds number of approximately 2500. This mode of agitation has also been used for the study of deposition of composite coatings.

(Nickel and Chromium Plating, J.K.Dennis, T.E.Such, Page 429)

High Frequency Resistance Welding(HFRW)

HFRW is a resistance-welding process in which a high-frequency alternating current is used for heating, followed by the rapid application of an upsetting force to cause coalescence. The frequencies are 10-500 kHz, and the electrodes make contact with the work in the immediate vicinity of the weld joint. In a variation of the process, called high-frequency induction welding(HFIW), the heating current is induced in the parts by a high-frequency induction coil. The coil does not make physical contact with the work. The principal applications of both HFRW and HFIW are continuous butt welding of the longitudinal seams of metal pipes and tubes.

(Fundamentals of Modern Manufacturing, Mikell P. Groover, Page 722)