الفهرس 
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Abstract
Bronze alloys consist of copper-based materials with the major alloying element
being tin. Many surface modification techniques such as chemical etching,
oxidation, electro deposition and sol-gel could be employed to improve surface
properties. Chili peppers were used to extract the organic compound employed in
this study. The extracted compound was subjected to Fourier-transform infrared
and ultraviolet spectroscopy analyses, with the results revealing that it is
primarily capsaicin [N-(4-hydroxy-3-methoxybenzyl)-8-methylnon-trans-6-
enamide) (HMMTE)]. Electrochemical deposition was employed in a twoelectrode cell where bronze was the anode and stainless steel (304) was the
cathode in 10 ml/L (HMMTE)/ distilled water solution under cell voltage equal to
30 volts. The contact angle increased from 48 to 132° after 1 hour of tin bronze
modification in a 10 ml/L HMMTE/distilled water solution (Improvement in
contact angle is about 3 times) that’s means a hydrophobic surface is formed on
the substrate. The corrosion resistance of tin-bronze in 3.5 % NaCl was
significantly improved, according to the electrochemical measurements. The
corrosion rate of tin-bronze decreases from about 10.22 to about 1.39 mpy after
surface modification that’s means there is an improvement in corrosion rate is
about 5 times. Energy-dispersive X-ray spectroscopy and Scanning electron
microscope were used to examine the surface morphology of the samples. The
existing phases were detected using X-ray diffraction. The results of surface
investigations revealed that following modification, a layer of red cuprous oxide
(Cu2O) formed on the surface layer, which improved corrosion resistance. The
base and surface modified samples were subjected to a 13-day salt spray test
according to ASTM B117. On the unmodified specimen, a green layer from
[CuCl2 and Cu46Cl24(OH)68-(H2O)4] (patina compounds) was observed, while the
red layer [Cu2O] was still visible on the modified specimen. The adhesion test
(using ASTM D3359’s X-Cut Tape Adhesion Test), surface roughness and micro
hardness were also investigated.