EXTRACT OF COMBRETUM MICRANTHUM AS CORROSION INHIBITOR FOR AL – SI – MG ALLOY IN SIMULATED SEA WATER ENVIRONMENT

Authors

  • SM Adams DEPT. OF METALLURGICAL AND MATERIALS ENGINEERING, KOGI STATE POLYTECHNIC, LOKOJA. KOGI STATE. NIGERIA
  • SA Yaro DEPT. OF METALLURGICAL AND MATERIALS ENGINEERING, AHMADU BELLO UNIV., ZARIA. KADUNA STATE. NIGERIA
  • M Abdulwahab DEPT. OF METALLURGICAL AND MATERIALS ENGINEERING, AHMADU BELLO UNIV., ZARIA. KADUNA STATE. NIGERIA
  • EE Oguzie DEPARTMENT OF CHEMISTRY, FEDERAL UNIVERSITY OF TECHNOLOGY, OWERRI, IMO STATE. NIGERIA

DOI:

https://doi.org/10.4314/njt.354.1199

Abstract

The leaf extract  of  Combretum micranthum (CM) was  tested  as  green  corrosion  inhibitor for Al-Si-Mg alloy in 3.5wt% NaCl solution using gravimetric and linear polarization methods at 300C, 500C and 700C, from 1, 2, 3, 4, 5 hours of exposure time with concentration of the extract 0, 0.2, 0.4, 0.6, 0.8 and 1.0 v/v  respectively. The result obtained indicate that the leaf extract of CM is a good corrosion inhibitor in the simulated sea  water medium. The inhibition efficiency of the extract increased with an increase in concentration of the CM extract and decreased with increase in temperature. On the other hand, inhibition efficiency (IE%) synergistically decreased on addition of surfactant (Monoethylamine). The adsorption of the inhibitor on Al-Si-Mg surface is exothermic, Spontaneous and is best described by Langmuir, Freundlick and El-Awady adsorption models. The calculated values of activation energy, enthalpy of activation entropy of activation, free energy of process is by physical adsorption. Equally, methanol extract CM is a good adsorption inhibitor for the corrosion of Al-Si-Mg in 3.5wt% NaCl solution. Tafel polarization analysis indicates that the studied plant extract is a mixed type inhibitor.

 

http://dx.doi.org/10.4314/njt.v35i4.25

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Chemical, Industrial, Materials, Mechanical, Metallurgical, Petroleum & Production Engineering

How to Cite

EXTRACT OF COMBRETUM MICRANTHUM AS CORROSION INHIBITOR FOR AL – SI – MG ALLOY IN SIMULATED SEA WATER ENVIRONMENT. (2016). Nigerian Journal of Technology, 35(4), 888-894. https://doi.org/10.4314/njt.354.1199