Electropolishing of an Fe-Ni-Co Alloy in Acetic Acid-Perchloric Acid Mixture

Aksu, Yasemin
Demirci, Gokhan
Karakaya, İshak
Among Fe-Ni-Co alloys, Kovar (53%Fe-29%Ni-17%Co) designated as ASTM F-15 (1), is a well-known glass-sealing alloy. It is also classified as low–expansion alloy (2). Low expansion is required to avoid internal stresses in applications that involve strong ceramic to metal joining such as in vacuum systems (3-6). Electropolishing is applied to obtain smooth metallic surfaces to gain low outgassing rates from the chamber walls in vacuum applications (7-9). The effects of current density, perchloric acid concentration and bath temperature on surface roughness and thickness change were investigated in acetic acid-perchloric acid electrolyte. It was found that current density, perchloric acid concentration and temperature of the bath had a decreasing influence on surface roughness in the given order. On the other hand, thickness change was found to have a direct correlation with the current density and was independent of bath concentration and temperature


Electrochemical Formation of Brazing Alloys on Metal Substrates
Ulu, F.; Karakaya, İshak; Demirci, G.; ERDOĞAN, MUSTAFA (2013-11-01)
CusilTM is a eutectic brazing alloy of 72% silver, 28% copper composition; used to join different materials. The large difference between the standard reduction potentials of silver (0.799V) and copper (0.337V) makes their electrochemical codeposition difficult. A complex ion bath containing KAg(CN)2, CuCN and KCN was used to bring the reduction potentials closer together. The effect of electrolyte concentration on composition and microstructure of electrodeposited Ag-Cu films was investigated at 25oC. A cu...
The Role of Electrolyte Composition on Codeposited Ag and Cu
ulu, fulya; Demici, Gokhan; ERDOĞAN, METEHAN; Karakaya, İshak (The Electrochemical Society, 2016-09-01)
The eutectic Ag-Cu composition is a common brazing alloy. A complex ion bath containing KAg(CN)2, CuCN, KCN and K4P2O7 was used to codeposit Ag and Cu. The effects of KAg(CN)2, KCN and K4P2O7 concentrations on the composition and morphology of electrodeposited Ag-Cu films was investigated in this study. A constant CuCN concentration of 0.1 M was used. The increase in KCN and KAg(CN)2 concentrations caused major increases in Ag contents, but increase in K4P2O7 concentration caused a minor decrease in Ag cont...
Investigation, Modeling and Design of a Cathodic Protection System for Hull Structures in Marine Environment
Aksu, R.; Uguz, R. O.; ERDOĞAN, MUSTAFA; Meco, H.; Karakaya, İshak (2016-06-02)
The corrosion behaviors of metallic components from hull structures of an amphibious vehicle in seawater were investigated. Selected steel types and aluminum alloys were subjected to accelerated corrosion tests in artificial seawater to collect data for simulation of cathodic protection with sacrificial anodes. The electrochemical data obtained via potentiostatic tests were used to simulate cathodic protection of the metallic components under seawater. Potential distributions in marine environment were eval...
Hasanlı, Nızamı; TAGIROV, VI (Elsevier BV, 1983-01-01)
The directional dispersion of IR-active modes of TlGaS2, TlGaSe2 and TlInS2 layersingle crystals has been investigated, depending on the angle between the phonon wave vector q and the optical c-axis. Owing to the possibility of preparation crystals with various orientations of reflecting surfaces with respect to the optical c-axis, it was of interest to check the applicability of the generalized Born and Huang theory of long-wave optical vibrations in uniaxial crystals to TlGaS2-type layer crystals.
ORCAN, Y (Elsevier BV, 1994-06-01)
The exact solution of the distribution of stress and deformation in an elastic-perfectly plastic cylindrical rod with uniform internal heat generation under generalized plane strain condition is presented. The treatment is based on Tresca's yield condition and the associated flow rule. The stress image points of the outer and inner plastic regions lie on two different edges of Tresca prism. With increasing heat generation parameter, the image points of the intermediate regions spread out through two side re...
Citation Formats
Y. Aksu, M. ERDOĞAN, G. Demirci, and İ. Karakaya, “Electropolishing of an Fe-Ni-Co Alloy in Acetic Acid-Perchloric Acid Mixture,” 2016, vol. 72, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36624.