The use of green inhibitor as corrosion protection of copper alloys

مقدم أطروحة جامعية

Zayn al-Abidin, Ali Yashar

مشرف أطروحة جامعية

Ujayl, Sami A.

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم هندسة الإنتاج و المعادن

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2013

الملخص الإنجليزي

Copper alloys used in heat exchanger are corroded in industrial water.

Three different natural green inhibitors are applied in studding the corrosion inhibition of copper alloys used as heat exchanger in industrial water.

The used inhibitors are extracted corn silk, eggplant juice and horse tail herb added in different concentrations and temperature to industrial water in which heat exchanger exposed to these conditions.

These alloys are studied at the above conditions using potentiodynamic polarization, optical microscope, scanning electron microscopy (SEM) and X-ray diffraction.

potentiodynamic polarization technique was used to evaluate the corrosion rate data.

Extracted corn silk, eggplant juice and horse tail herb were used as green organic corrosion inhibitor, while industrial water was the corrosive solution the variable conditions used in these investigation are (150 to 350ppm at 298 k corn silk and eggplant juice for brass and aluminum bronze, 150 to 1350 ppm at 298 k, 150 to 550 ppm at 308 k and 150 to 1150 ppm at 318 k horse tail herb for brass, 150to 450 ppm at 298 k, 150 to 450 k at 308 k and 150 to 450 ppm at 318 k horse tail herb for aluminum bronze).

Different parameters, such as polarization parameters used to calculate corrosion rate, inhibitor efficiency and activation energy were obtained.

When extracted corn silk and eggplant juice are used as inhibitors it was found that the corrosion rate increases with an increase in concentration of inhibitors (150 to 350 ppm) at 298 k from potentiodynamic polarization measurements.

This indicates that these materials are not recommended to use as inhibitors for copper alloys in industrial water.

Inhibition efficiency of 92.2 % at 298 k was achieved with the addition of 1350 ppm of horse tail herb from potentiodynamic polarisation measurements for brass and the best inhibitor efficiency for aluminum bronze is 86% at 318 k with addition of 350 ppm.

The corrosion rates were observed to decrease with an increase in concentration of horse tail herb but the corrosion rates in the used conditions increase with temperature increase.

Potentiodynamic curves show that the presence of extracted horse tail herb in industrial water affects of both the anodic and cathodic processes, decreases the corrosion current density and shifts the corrosion potential towards more noble values; the inhibitors are mixed type inhibitors.

From the temperature dependences, the apparent activation energy in industrial water was determined in the presence of all studied compounds, found to be inferior to the activation energy in absence of inhibitor.

Adsorption of extracted horse tail herb on the copper alloys surface in industrial water confirms formation of an adsorbed layer on the copper alloy surface.

A change of morphology was observed after the addition of horse tail herb as shown from optical microscope, SEM and X-ray analysis observations.

These results indicate that extracted horse tail herb is a successful green inhibitor for copper alloys in heat exchanger in industrial water.

التخصصات الرئيسية

العلوم الهندسية والتكنولوجية (متداخلة التخصصات)

الموضوعات

• سبائك النحاس

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-432984