Fast Fourier transform on analysis of Portevin-Le Chatelier effect in Al 5052

Tensile tests were conducted with polycrystalline samples of Al5052 by deforming at room temperature on three different strain rates where the Portevin-Le Chatelier (PLC) effect was observed. The data of PLC effect serrations were obtained by subtracting moving average from the experimental stress-time data, and then analyzed by using Fast Fourier transform (FFT) to explore characteristics in frequency domain. The results indicate that the amplitude-frequency distribution is in different type from each other with different strain rate. And strain has little influence on FFT results. Moreover, through mathematic analysis on FFT results, the distribution characteristic curves have been obtained.