Corrosion control of Cu-Ni alloy in hydrochloric acid by amines compounds

Inhibitors of corrosion are chemicals materials that, when added in little amount to an environment impede the development of corrosion reactions. The inhibitors use is represent one of selections of protecting alloys of metals from corrosion, which leads to protect surfaces of metal in corrosive environments. Most organic compounds inhibitors that contain nitrogen, are effective inhibitors in the acidic medium, especially hydrochloric acid. Copper represents noble metal and requiring very strong oxidants for its dissolution or corrosion. The electrolytic plating and chemical dissolution are the main processes used in the electronic devices fabrication. Alloys made of copper are widely used in chemical processes especially when heat and electrical conductivity are important factors in these processes, there is very wide range of copper metal using in commercial applications. The corrosion inhibition or corrosion control of alloy made of copper (Cu) - nickel (Ni) in hydrochloric acid (6% HCl) at the range of temperature of (40-60 degrees C) was studied in the absence and presence of the inhibitors used in the experimental work were ethylenediamine (EDA) and tetraethylenepentamine (TEPA) at the range of concentration of (1-10 g/l). The technique of weight loss was used to evaluate the data of corrosion rate. EDA & TEPA were used as organic inhibitors of corrosion. Corrosion rate decreased with increases of inhibitor concentration, while it increased with increases of temperature. The adsorption isotherm of both inhibitors on metal surface used in this research was found to follow Freundlich. The kinetic-thermodynamic data and adsorption isotherms were used to evaluate the values of equilibrium constants (K).