Gökhan Demirci

Formation of gold-plated electroformed copper structures

Abstract Gold-plated electroformed copper structures are used to protect sensors from stray radiation and improve the image quality in infrared cameras, imaging systems, missile guidance systems and several other devices. These multilayer electroformed objects have tight dimensional and weight tolerances. Furthermore, their internal and external surfaces often exhibit low and high emissivity, respectively. Reflectivity at the outer surface was achieved by gold electrodeposition. Moreover, inner copper layer was converted to copper oxides to obtain high absorption. Characterisation of the coatings were done in terms of microstructure, roughness, infrared specular reflectivity of layers, texture and stress formation by SEM, profilometer, FTIR, parallel beam XRD and deposit stress analyzer, respectively.

Molten Salt Electrolysis of MgCl2 in a Cell with Rapid Chlorine Removal Feature

An experimental electrolytic magnesium production cell was designed to remove chlorine gas from the electrolyte rapidly and demonstrate the beneficial effects of reduced chlorine dissolution into the molten salt electrolyte. The back reaction that is the main cause of current losses in electrolytic magnesium production was reduced as a result of effective separation of electrode products and decreased contact time of chlorine gas with the electrolyte. Moreover, smaller inter electrode distances employed and lower chlorine gas present on the anode surface made it possible to work at low cell voltages. Electrolytic cell was tested at different current densities. Energy consumption of 7.0 kWh kg-1 Mg that is slightly above the theoretical minimum, 6.2 kWh kg-1 Mg, at 0.68 Acm-2 anodic current density was achieved for a MgCl2/NaCl/KCl electrolyte.