In this paper the passive layer cracking process that occurs under tensile stresses and anodic polarization conditions on AA1050, AA5052, AA5056, and AA7005 aluminum alloys was examined by means of direct current (dc) technique, dynamic electrochemical impedance spectroscopy (DEIS), and acoustic emission (AE). Research revealed the advantage of DEIS and AE methods over the dc one. It was also possible to determine the exact moment of the passive layer cracking on investigated aluminum alloys. (c) 2006 The Electrochemical Society. All rights reserved.