Investigation of crack growth behavior in aluminum alloy used in engine components, by acoustic emission method

Using aluminum alloys is common in the engine industry due to low weight, high heat transfer and proper ductility. Detecting damages in aluminum structures is also important for higher reliability. One way to detect defects is the acoustic emission (AE) approach. Therefore, the objective of this article is to detect damages in open-hole aluminum alloy under tensile loadings. Firstly, the specimen was tested and elastic waves according to cracks from the hole were measured by AE sensors. As a result, nominal and pure stress concentration factors and the maximum stress around the hole were calculated by two relations and compared. For the fracture frequency in the specimen, the fast Fourier transform was utilized and the AE maximum voltage of the failure was obtained. Then also, the cumulative AE energy was compared to the crack length and a non-linear relation was fitted to experimental data.