Browsing by Author "N.Nageswara Rao"

Now showing 1 - 4 of 4

CORROSION STUDIES IN AQUEOUS-ORGANIC BINARY SOLUTIONS I COPPER IN WATER - DMF MIXTURES.
(1984) N.Nageswara Rao; V.B. Singh
Corrosion behavior of copper in N,N-dimethylformamide-water mixtures has been studied at 30 plus or minus 1 degree C galvanostatically covering the whole range of solvent composition. The solvent composition has been found to have marked influence on the observed active, passive behavior of copper. Copper exhibited passivity in solvent mixtures containing above 40m///o DMF on impressing a small constant current, while larger currents are needed to observe passivity in solvent compositions below 40m///o DMF. The corrosion behavior has been explained in terms of various physicochemical properties of solvent mixtures and a semiempirical view has been speculated for the dissolution of copper.
CORROSION STUDIES IN AQUEOUS-ORGANIC BINARY SOLUTIONS. COPPER IN ADMIXTURES OF WATER AND N-METHYLFORMAMIDE.
(Natl Research Council of Canada, 1984) N.Nageswara Rao; V.B. Singh
This paper presents the results of corrosion studies of copper metal in various binary mixtures of N-methylformamide(NMF) and water by potentiostatic method. N-methylformamide is characterized by a high dielectric constant and is a powerful dissociating solvent. These binary mixtures are found to be corrosive to copper. Addition of small amount of NMF (0. 5 moles) to water increased the critical anode current density by a factor of 10**1-10**2. Scanning Electron Micrographs of the test-specimens after anodic polarization revealed pitting. The anodic behaviour of copper in above binary mixtures has been explained by complex forming ability of NMF. Spectral studies also confirm the complex formation.
Electrochemical and corrosion behaviour of nickel in formamide-water mixtures
(1991) V.B. Singh; N.Nageswara Rao
An electrochemical study of nickel in various mole percent (m%) compositions of formamide and water has been carried out potentiostatically. Active-passive behaviour has been observed. The critical current density for the passivity is dependent on the content of formamide, and has been rationalized in terms of solvation and diffusion. The results have been further substantiated by the studies performed under deaeration, temperature-variation and stirring conditions.
Electrochemical and corrosion studies of copper and nickel in mixed N-methylformamide-water solutions
(1985) N.Nageswara Rao; V.B. Singh
An electrochemical and corrosion study of copper and nickel in various mol percent (m/o) compositions of N-methylformamide and water has been carried out potentiostatically at 35 ±1 °C. Frequent active-passive transitions are observed and the critical current density for passivity is found to be dependent on the content of N-methylformamide in the solution. Nickel is found to be quite resistant to these solutions. © 1985.