This study aimed to compared mechanical properties and failure mechanisms in ferrite and martensite samples, using Acoustic Emission (AE) Non-Destructive Testing (NDT). The purpose of this study is to identify the phases of ferrite and martensite by analyzing the parameters of AE. Tensile testing was performed on the samples and AE signals were recorded. The Sentry Function (SF) and Fast Fourier Transform (FFT) were used to analyze signals. The results of the martensite sample show that the SF is almost constant at the beginning. This indicates a relative balance between the AE energy and the strain energy. Then the SF took a downward state, which demonstrates a greater ratio of acoustic energy to strain energy. Frequency distribution, one of the best parameters to identify the failure mechanisms in materials for the ferrite sample, is significantly in the range of 175 kHz, while for the martensite sample, this range is between 520 and 700 kHz. تفاصيل المقالة

In this study, the effect of ferrite grain size on mechanical properties and failure micro-mechanisms of materials was investigated by using acoustic emission (AE) non-destructive testing (NDT). AE signals were obtained from tensile tests of fully annealed ferrite samples and the effective AE parameters for each sample were analyzed from the AE waveforms. Due to annealing, the ferrite grain size was different in each sample, which affected the AE signals, and to analyze the AE signals, the Sentry Function (SF) and Fast Fourier Transform (FFT) were used and the results show that performing a full annealing operation to change the grain size at different temperatures almost did not significantly affect the frequency parameter, which has a range of about 175 kHz. In addition, the amplitude was about 30-40 dB, which indicates the deformation of the ferrite, and also the amount of AE energy released during the tensile test was lower than the strain energy. تفاصيل المقالة