Category Archives: General

Corrosion protection of 6061 Al-15 Vol. Pct. SiC(p) composite using a biopolymer- An electrochemical approach

Posted on by

The influence of biopolymer starch as corrosion inhibitor on 6061 Al-15 vol. pct. SiC(p) composite in 0.05M hydrochloric acid was studied by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) technique. The surface morphology was studied using SEM, EDX, AFM and XRD techniques. The results showed that the inhibition efficiency of starch increased with increasing inhibitor concentrations and also with increase in temperatures. Starch acted as a mixed inhibitor and underwent chemical adsorption following Langmuir adsorption isotherm. 

To read the whole article please:
    

Malonic Acid as Corrosion Inhibitor for Carbon Steel in 1 M Hydrochloric Acid Solutions

Posted on by

The protection effect of malonic acid on carbon steel corrosion was studied in aerated stagnant 1M HCl solutions at 250C. Measurements were conducted under different experimental conditions using weight loss, Tafel polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. malonic acid was found to be good inhibitor of carbon steel corrosion in1 M HCl. The adsorption of this inhibitor is found to obey the Langmuir adsorption isotherm. The calculated activation energies proposed that the inhibitor molecules being physically adsorbed onto the metal surface. Polarization data revealed that this compound behave as mixed type inhibitor.

To read the whole article please:
    

Square Wave Pulsating Overpotential Treatment of Chromic Acid Solution

Posted on by

Systematic investigation of square wave pulsating overpotential (SWPO) treatment of a chromic acid solution is presented. Some preliminary potentiodynamic scans, potentiostatic deposits, potential steps and capacitance vs. potential curves were measured in order to establish the practical range of the SWPO signal parameters. The results show that properly adjusting the electrochemical parameters of the cyclic alternating potential perturbation it is possible to obtain cracked or crack free metallic chromium or chromium oxide/hydroxide mixed coatings. The different deposit morphologies were characterized through scanning electron microscopy and their chemical composition and micro hardness was measured. Some insight into the possible mechanisms of coating growth under this potential cycling treatment is given.

To read the whole article please:
    

Overview of the UK Surface engineering sector

Posted on by

Surface engineering is a sub-discipline of materials science and covers a multitude of processes such as electroplating, anodising, electro-polishing, heat treatment processes, physical vapour deposition and the like. The term surface engineering was promoted by, amongst others, Professor Tom Bell of the University of Birmingham defining it as “the design of surface and substrate together as a functionally graded system to give a cost-effective performance enhancement of which neither is capable on its own”. Imagine a world without cars, aeroplanes, trains, computers, mobile phones, medical implants, buildings, electronics, in fact virtually no manufactured products – that’s a world without surface engineering. Thus, the application of surface engineering is vital to the success of almost every commercial and industrial product: from aero engines to aeroplanes, from iPods to surgical implants and from razor blades to racing cars.

To read the whole article please:
    

Adsorption and Corrosion Inhibition Characteristics of Some Thiophene-3-Carbohydrazide Derivatives on Low Carbon Steel in Hydrochloric Acid Solutions

Posted on by
Fig. 7: Molecular orbital plots of organic compounds

New compounds of corrosion inhibitors namely amino-N’-(3-(hydroxyimino)butan-2-ylidene)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbohydrazide (1), amino-N’-(thiophen-2-ylmethylene)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbohydrazide (2) and amino-N’-(1-(pyridin-2-yl)ethylidene)-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbohydrazide (3) were synthesized and its inhibiting action on the corrosion of carbon steel in 1 M hydrochloric acid at 25ºC was investigated by various corrosion monitoring techniques. A Potentiodynamic polarization, AC impedance and electrochemical frequency modulation methods have been used. Potentiodynamic polarization studies showed that these derivatives were mixed type inhibitors. The effect of temperature on the corrosion behavior of carbon steel in 1 M HCl with the addition of these compounds were studied in the temperatures 25 and 45ºC. The adsorption of these inhibitors on carbon steel surface from hydrochloric acid obeyed the Langmuir adsorption isotherm. Quantum chemical method is used to explore the relationship between the inhibitors molecular properties and their inhibition efficiency.

To read the whole article please: