Analysis of Ethanol Extract of Capsicum Pedicles for Corrosion Prevention of Electro-Discharge Machined Mild Steel Surface in 0.5M NaCl

Abstract

The electro-discharge machining (EDM) is a fast way to machine the surfaces of different materials, especially hard metals. The corrosion behaviour of any metal is highly dependent on the exposed surface. The EDM with different current values and depth of machining (DOM) can affect the surfaces accordingly. This work reports the corrosion behaviours of the mild steel (MS) surfaces machined by EDM with different current (10 and 20 A) and depth of machining (300 and 700 µm). The corrosion investigation of EDM MS in 0.5 M NaCl has been carried out by electrochemical techniques (ET) and scanning electron microscopy (SEM). Furthermore, ethanol extract of capsicum pedicles (CPEE) has been synthesized and characterized by FT-IR spectroscopy (FS) and coated on EDM surfaces by drop casting method (DCM) using 100 µL of CPEE. The coated surfaces have also been investigated by ET and SEM. The results have shown that increase in current from 10 A to 20 A has lowered the corrosion resistance of MS. Also, increase in the depth of machining has lowered the corrosion resistance of MS. The CPEE coated MS showed greater corrosion resistance than uncoated MS. However, the coated MS have not shown the greater corrosion resistance than MS. The reason could be claimed as increase in irregularity of the surface after EDM. It is also observed that irregularities of the surfaces have increased with current and DOM due to more heat generation.