Fig. 9: Eddy current array result (left) and Ultrasonic phased array result (right) (Kathir & John 2005)
Figure 9 shows the Eddy current array scan result (left) for a specimen. This experiment is actually Experiment No. 3 from the table. The specimen contains corrosion damage which was created exclusively for this experiment by immersing the sample in the electrolyte for approximately 30 minutes and a circular notch of 0.2mm deep was made by electric discharge machining. Both the array coils were excited at a frequency of 15 kHz for a sample thickness of 1mm. On the right hand side is the corrosion damage of electric discharge machining notch by Ultrasonic phased …show more content…
Aluminum Oxide Trihydrate (Al (OH) 3): A white powder which is insoluble water but soluble in hydrochloric or sulfuric acid.
Aperture: In phased array testing, the width of the transducer element or group of elements pulsed simultaneously.
Chemical Etching: A process when acids, bases or other chemicals dissolve materials such as metals, semiconductor materials or glass.
Electrical Conductivity: Electrical conductivity is a measure of how well a material accommodates the movement of an electric charge. It is the ratio of the current density to the electric field strength.
Electric Discharge Machining: A machining method primarily used for removing hard metals by producing a rapid series of repetitive electrical discharges.
Electrolyte: Any substance containing free ions that make the substance electrically conductive.
Frequency: The number of complete cycles per second in alternating current direction.
Magnetic field: Defined by measuring the force the field exerts on a moving charged particle, such as an