Quantitative Nondestructive Evaluation of the Aluminum Alloy Using the Sheet Type Induced Current and the Single Sensor Scanning

Single sensor scanning (hereafter SSS) used to inspect cracks on paramagnetic materials can measure the distribution of the root mean squared value (RMS) of the magnetic field around crack tips quantitatively when sheet type current is induced on the specimen. The vertical direction magnetic field alternates to the surface of the crack tips because the sheet type induced current on the specimen is distorted by the existence of the crack in an SSS system. The RMS distribution of the magnetic field, which can be measured by using SSS, depends on the crack size and shape, so it can be used to evaluate a crack size quantitatively. An algorithm of quantitative nondestructive testing and evaluation of cracks of various shapes and sizes on the aluminum alloy, Al7075 is proposed in this paper.