AE response of α-brass during stress corrosion crack propagation

The present work was aimed at characterizing the acoustic emission (AE) response of α-brass during SCC propagation. For that purpose, slow strain rate tensile tests (SSRT) under potentiostatic control were performed in a 1 M NaNO2 solution and in Mattsson’s solution. The differences between the AE signals generated by transgranular and intergranular stress corrosion cracking (SCC) were analysed. Results show that the AE activity during the propagation of TGSCC is various orders of magnitude higher than the AE activity during the IGSCC propagation. However, the mean amplitude and rise time of the AE signals registered during the propagation of TGSCC are similar to the AE parameters of the signals registered during the propagation of IGSCC. The measured AE activity was associated with the mechanical tearing of the metallic ligaments left behind by the propagating crack.